Making an alpha layer for mesh clothing
This is how I use Blender to make a guideline template AO map to use to create an alpha layer for my mesh clothing that I make in the DigiWorldz Grid of OpenSim.
It's rough and very amateur but it works for me and might just work for you.
You can use an avatar out of one of the 5 standard sizes that you can download here... http://dl.dropbox.com/u/6003454/Standard%205%20sizes.zip
Or you can use the Avastar avatar that you can get here... http://blog.machinimatrix.org/avastar/