Instagram was without a doubt my favorite app of 2010. That being said, the one thing it lacked was a way for users to view their galleries outside of the app. Luckily, three individuals have taken it upon themselves to address this (links below).
The first page is by @mislav, who was kind enough to provide a tool to help retrieve User IDs. All you need to do is plug in the URL of an uploaded photo and go from there.

This next page is by @gruzilla, and it differs from the first in that we’re able to see who has liked and/or commented on a photo. To see your photos on this page, paste http://www.abendstille.at/instagram/index.php?user= into the address bar and be sure to include the User ID that you got on the first site.

The last site (by @juansanchez) is a little different, as it pulls from Instagram photos uploaded to Flickr. All you need to do is enter your Flickr username and you’re good to go.

If you know any other sites utilizing the Instagram API, please reply to this thread or message me. Thanks!