Blender 2.62 does a good job of exporting a 3D scene in the Collada (DAE) format for use as an overlay in Aurasma Studio. You just need to make sure you interpret the newest version of the Aurasma 3D Guidelines in a Blender 2.62 context. For a Blender 2.62 user the most important guidelines to follow are:

• Models need triangulated faces (Edit mode > Ctrl+T)
• No more than four lamps (lights) although three are recommended
• Models are to have no more than one map/texture
• Create a .tar archive to upload to Ausrasma Studio made up of .dae (Exported from Blender 2.62), .png (Texture) and a .png thumbnail (256 x 256).

This video is an example of a simple 3D cube augment produced with Blender 2.62 and Aurasma Studio.