@Cry-Wich: EP1 wrote a tutorial on how to use the scripts with Far Cry. The tutorial works for Crysis too.http://farcry.crymod.com/filebase.php?cat=6&letter=B
The only thing to be careful about with Crysis and Blender is that you must put your textures in a subfolder of the Game folder for export to work properly. This does not need to be in your official Crysis install Game folder, you can just mimick the file structure of the Game folder elsewhere, which you may prefer in order not to clutter up your Crysis install.
For example, in my setup I have something like
...Documents/My Crysis Stuff/Game/Objects/Amorilia/monkey.cgf
...Documents/My Crysis Stuff/Game/Textures/Amorilia/bricks.dds
After texturing and selecting the Textures/Amorilia/bricks.dds texture in Blender, when exporting, the exporter will recognize the /Game/ part in the path and cut off the texture path there. So when you then create a pak file containing the Objects and Textures folders above, and put that in your crysis Game folder, the game will find the texture referenced in the cgf. (Aside, the texture does not need to reside in Levels, so it is no problem to share textures between different levels.)
Once the crymod wiki is open to the public, EP1 and I will wikify the tutorial.