Facebook and Etsy photo dimensions ... reference

FACEBOOK

Coverphoto: 851w x 315h
Profile: 180w x 180h
Custom Tab Photos: 111w x 74h
Shared Photo: 404w x 404h
Highlights & Milestones: 843w x 403h
Tab page: 810w

http://www.jonloomer.com/2012/03/07/dimensions-for-facebook-timeline-for-pages-infographic/#

http://www.handmadeology.com/getting-creative-with-your-facebook-fan-page-timeline-exact-dimensions-examples-and-free-template/

ETSY

Shop Banner:  760w x 100h
About Page Photo: 1024w x 768 h  (760 x 430)
Main image: 570w x 460h (with your item centered within the 460w x 460h)
     if you prefer more detail: 1024w x 768h
Avatar/Profile Photo: 75w x 75h
Team Logo: 170w x 100h

Gallery/Treasury Photos:  170w x 135h or 155w x 125h ... depending on where they are used
Thumbnails: 75w x 75h or 50w x 50h ... depending on where they are used

http://www.etsy.com/help/article/451
http://www.etsy.com/help/article/203

http://kinkymelcat.blogspot.com/2008/07/how-to-create-knockout-photos-for-etsy.html

http://www.gotogreatpanes.com/blog/2010/04/08/image-cropping-for-etsy/