You'd best visit www.3dlinks.com
for any info you might need, they have a whole section on converters of all types as well as all the links you'll ever need for models, etc. I have to say that the 2 or 3 converters I've tried pretty much sucked, but I dont have the money for the full-on commercial packages so I cant comment on them. I dont even know what format Blender models come in, so I dont know which converters might be useful to you anyway. Personally the best converter I ever found was an actual 3D program itself, Pixel 3D
, which could load and save in a ton of different formats.