ShadowNinjaDudeMan- thankyou.
Hendrich- i'm not sure that i've got the patience to make a complete map, but yes, blender can be used to make some nice details for maps. a nice trick is to do the bulk of the map in gtkradiant, compile it, decompile the map's bsp to an ase model and load that into blender to use as a guide. this enables you to make models that line up perfectly with maps.