Since we launched our API, avid FriendFeed users and developers have built all sorts of cool applications. One of our favorites is Mail2FF, which lets you easily post pictures to FriendFeed via email. Built by Gary Burd, it lets you post messages directly to FriendFeed using a special email address that consists of your FriendFeed nickname and your FriendFeed Remote Key. (Your remote key is a secret combination of words and numbers that allows third party software to interact with FriendFeed on your behalf, without the need to reveal your real password.)
For example, to post photos to my feed, I just attach them in an email to firstname.lastname@example.org.
Check out my full video tutorial on Mail2FF below.