This is slightly different from Threadless’s photo gallery. Amazon explains the reasons behind this feature,
Sometimes product descriptions and manufacturer supplied images are not enough. Here’s your chance to help millions of fellow customers learn more about how a product looks, behaves and performs. Think of customer uploaded image as reviews in pictures.
Another move by [...]

I don’t know when flickr added this feature, but I am so happy that they did. Now only if they’ll do that for Photostream.

Wow, I think I’ll go with the 25 billion songs site instead of these other two, despite all three ranking equally lame on account of their domain names. So these are the “highly relevant” Adsense ads I should be seeing in my Gmail, Google?

Being a small happy company, we shunned anything “enterprisey” like Outlook/Exchange and have been happy with POP3 accounts and the freedom of using whatever mail client for our e-mail needs. However, our POP3 accounts’ webmail (SquirrelMail) left much to be desired in a web-based e-mail system.
Gmail introduced a new feature last week [...]