The beamerposter ^[1] package is quite nice.

Examples:

Elena Botoeva has written a new package for creating posters with TikZ, called fancytikzposter ^[1]. There are already five templates with different node shapes and colors.

Sample ^[2]:

Note that as indicated by the author ^[3],

NOTE that we joined our efforts with the tikzposter team, which resulted in an improved version 2.0 of the tikzposter class that you can find in http://www.ctan.org/pkg/tikzposter. This class combines both good structure and nice layouts. The official webpage of our project is https://bitbucket.org/surmann/tikzposter/wiki/ (under construction).

I am not going to maintain this style.

See the tikzposter answer ^[4].

baposter ^[1] is a LaTeX class designed for posters.

Look at the example file included in the class' zip file and you will probably find your way.

A few quick tips :

• You can position boxes by giving them names with name=abc and positioning other boxes using below=abc
• You can set the total number of columns in the document by giving "columns=X" parameter in the \begin{poster} parameters.

EDIT - one of the example posters:

The already mentioned fancytikzposter ^[1] by Elena Botoeva now merged with tikzposter to form tikzposter 2.0 ( Bitbucket wiki ^[2], CTAN resource ^[3]) which is a great solution to build beautiful posters:

Previously, I wasted a lot of time trying to get sufficiently large paper sizes, sufficiently large fonts, etc. And even when I was successful, I had difficulties with PDF previewers that e.g. waste ridiculous amounts of memory if you open an A0 document. Finally I realised that I can simply create my poster in A4 size. Then you just ask that it's printed in A0 size (a single click in Adobe Reader printing dialog; in most cases, even your local university press can do it). You can easily preview your poster by simply printing it on an A4 printer.

I usually use 8pt fonts (\footnotesize) in my A4 posters. It translates to 32pt fonts when scaled to A0, which seems to be a suitable size for a typical conference poster. Nowadays I'm simply using the article class and settings such as

\pagestyle{empty}
\setlength{\parindent}{0pt}
\raggedright

You can use the textpos package to place "text boxes" using absolute coordinates. Other useful packages include color, titlesec, enumitem, and psnfss.

For very large fonts (e.g. poster title), you can use something like \fontsize{26}{30}\selectfont – alternatively, you can use the \scalebox command. For layout tweaks: \hspace, \vspace, \makebox, \parbox, \raisebox. For drawing lines and boxes: \rule.

I have some advice on this topic elsewhere, which includes pointers to other resources: Using LaTeX to produce conference posters ^[1]

Myself, I think that the most useful package for a task like this is the textpos package ^[2] (disclaimer: I wrote that, as a spinoff from the task of laying out posters).

In the site LaTeX Templates ^[1] there are three downloadable Conference Posters templates: baposter Portrait Poster, Dreuw & Deselaer's Poster and Jacobs Landscape Poster.

Example: Jacobs Landscape Poster ^[2]

Description:

This poster template features a clean sectioned look suitable for presenting research at a conference. Important information is highlighted with colored boxes and each section within the poster is clearly separated from the others. The layout of the template contains four columns but this can be changed to accommodate varying amounts of information or figures. Examples of a table, figure, equation, list and bibliography are present in the template to provide a starting point for any requirement you may have for your own poster.

Original Author:

This template was originally created by the Computational Physics and Biophysics Group, Jacobs University and was then modified by Nathaniel Johnston. Finally, it has been extensively modified for this website.

uses

\documentclass[final]{beamer}
\usepackage[scale=1.24]{beamerposter}
\usetheme{confposter} 

a0poster ^[1] and sciposter ^[2] are two document classes that are designed to help you make posters. a0poster worked better for me.

There is also the umbcposter package (similar to baposter). You can download it from: math.umbc.edu/~rouben/umbcposter ^[1]

The site also provides a good on-line users' guide, as well as a sample poster to get started and a gallery of posters that have used the package.

Here is part of the sample poster provided:

% sample.tex % A sample UMBCposter.% Rouben Rostamian, February 2010

\documentclass[paper=a4paper,landscape,dvipsnames]{umbcposter}
\begin{document}
\newcommand{\mytitle}{
\begin{tabular}{c}
    \LARGE\sc This is the title \\[0.6ex]
    \Large\sl Rouben Rostamian\\
    \Large UMBC
\end{tabular}
}
\posterinit{
%grid,
background style = {left color = Apricot, right color = white},
title = {\mytitle},
right logo,       % use default
left logo,        % use default
box/border style, % use default
box/header style, % use default
box/body style = {bottom color=blue!10, top color=red!5},
box/all rounded,
}
\boxit{col = 0, at top, name=box1}{Title of Box 1}{
\begin{itemize}
    \item col = 0
    \item at top
    \item name = box1
\end{itemize}
}
\boxit{col = 0, below of=box1, name=box2}{Title of Box 2}{
\begin{itemize}
    \item col = 0
    \item below of = box1
    \item name = box2
\end{itemize}
}
\end{document}

Since version 4.10, tcolorbox ^[1] offers a poster library which combines its already known capabilities for colorful boxes creation with baposter positioning system.

The starting point for boxes distribution over the poster is a typical matrix (row and columns) but boxes placement or size are not restricted to the scheme. Boxes length can be automatically computed with other boxes as reference. And boxes can be broken and its content flow between fragments.

Following code shows a little example. You can find a more detailed example in tcolorbox-example-poster ^[2] tutorial or in Thomas F. Sturm ^[3] answer to Creating this poster layout using minipages ^[4]

\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage[poster]{tcolorbox}
\usepackage{lipsum}
\usepackage{lmodern}

\pagestyle{empty}

\begin{document}
\begin{tcbposter}[
    coverage = {
        spread,
        interior style = {top color = white, bottom color = brown!80!black},
    },
    poster = {
%       showframe, 
        columns=3, rows=5},
    boxes = {
        colframe=brown!80!black,
        colback=brown!50,
    },
    fontsize = 12pt,        
]

\posterbox{name=title, column=1, span=3, below=top}{
{\Large This is a very nice poster made with \texttt{tcolorbox}}\\tex.stackexchange.com}

\posterbox[adjusted title=Introduction]{name=intro, column=1, span=2, below = title}{\lipsum[2]}

\posterbox{name=logo, column*=3, span=.5, above=bottom}{
\begin{tikzpicture}
\fill[yellow] circle (1cm);
\fill[red] (45:.5cm) circle (1mm) (135:.5cm) circle (1mm);
\draw[red, line width=1mm] (215:5mm) arc (215:325:5mm);
\end{tikzpicture}
}

\posterbox[adjusted title=Conclusions]{name=conc, column=2, span=2, above = logo}{\lipsum[2]}


\posterbox[adjusted title=Acknowledgments]{name=ack, span = 2.5, column = 1, between = conc and bottom}{\Huge  Thank you to Thomas F. Sturm}

\posterbox[adjusted title=Description, colback=white]{name=desc, sequence = 1 between intro and ack then 2 between intro and conc then 3 between title and conc}{\lipsum[1-4]}

\end{tcbposter}
\end{document}

I recently dicovered baposter ^[1]. It is based on pgf so tikz related things will work fine. The macros are fairly easy to understand and Brain (the author) shows quite a lot of examples.

All I can say that I recently won the poster price at a conference with a baposter designed poster.

The TeX FAQ has an entry Creating posters with LaTeX ^[1]. I also have a tutorial Creating Technical Posters with LaTeX ^[2] as well as a tutorial on creating LaTeX posters with a GUI ^[3]. My flowfram package has already been mentioned in a comment. It has an example poster in the samples directory ^[4].

Faced with the task to provide a poster template for our institute I just created a small github repository ^[1] with complete self-explanatory examples for:

1. beamerposter ^[2] with columns
2. beamerposter with package textpos (recommended by the beameruserguide)
3. beamerposter tcolorboxes ^[3] (using its poster library)
4. a baposter.cls ^[4] fork

In particular I discuss the problem of vertical alignment which can be a bit unnerving in some approaches. Given the existence of a predefined beamer style file.
I found the tacolorboxes approach to be the most flexible, but in the example posters I also discuss the alternatives in more depth.