I don't know whether this site has been mentioned or not but i've found it quiet useful for my needs. Hopefully someone will find it as helpful as i have.
I use this site mainly for thumbnails, speed sketching (usually 3 min max per pose) and to get a better understanding of the human form.
1) Once on the site click on the gallery (should be on the left hand side in the menu bar) click 3d gallery (new page should open)
2) click on the 3D models section...you'll get a chose of about 60 models but just choose one that's visible on the page (double click)
3) Once the you've made your chose you'll get all this information about the model...scroll down and click on 3d view...once its done loading rotate the model to the pose u desire.
let me know if it helps.
this link should work...i've been to the site twice just to double check it...if it doesn't work here's the adress - www.anything3d.com