Poster Design

Several programs can be used to prepare a good looking poster.
Depending on what you are familiar with, you can use for instance LaTeX, Inkscape or even Powerpoint.
A more powerful (but not free!) solution is offered by Adobe Illustrator,
which allows to add extra graphical charm to your research results
(if you are patient enough to look for tutorials on the internet)

LaTeX

Inkscape

Powerpoint

..anyone?

Adobe Illustrator

Where to Get It

You can purchase a greatly discounted version of the last Adobe Illustrator from Surfspot.nl
by selecting "Universiteit Utrecht" in the INLOGGEN panel:
surfspot.nl
This way you will actually get the whole Adobe suite, including Photoshop and InDesign
(also useful in many situations, from preparing pictures for your paper to setting your thesis layout).

Tutorials

A good place to start from: Illustrator official tutorials page
you can just look on the internet for Illustrator tutorial,
commands used in previous versions generally apply to later ones (ex. CS5 tutorials while using CS6)

some recommended videos:
point vs area type (important for proper text flowing!)
text wrapping (make text wrap around shapes/images)

Poster Templates (with Utrecht University graphics)

Illustrator Template (CS6 version)

Here is a general template with the Utrecht University institutional graphics and logos:

Notice that this was saved in Adobe Illustrator CS6 and might present changed objects groupings
when opened in a different version of the program.
The file is organized in a Background layer, which is locked to prevent further changes
(but you can unlock it through the Layers control panel),
and a Text layer, where you can select and modify all the variable elements such as text and images.