Divvyshot: just shake your iPhone to share photos
The flashiest way to share photos with Divvyshot is to put two iPhones together and shake them. This method allows you to quickly share tons of photos between two phones without having to actually transfer the files – the person you're sharing with just gets access to the already-uploaded photos on Divvyshot, and their phone pulls files from the cloud.
The iPhone-quality versions of the photos aren't too shabby -- and anyone who has access to a particular album can manually download high-res versions via the web. The service also integrates with Flickr, Twitter, and Facebook, making sharing on multiple sites a snap.
If you don't want to have a Facebook or Flickr account just to share photos with your friends, Divvyshot is worth a look as it seems to be positioning itself as the easier-to-use alternative.