Automagically Building User Profiles with Gravatar
The Gravatar API offers a simple shortcut to automagically build user profiles, including the user’s mug shot. Construct the user’s email hash by md5’ing her email address, then request the user’s public image by constructing her unique URL. Essentially, a signup wizard needs to just ask the user for her email address. No permissions needed. This allows Gravatar-enabled users (usually bloggers on wordpress) to skip uploading the profile photo altogether. Nice alternative to Facebook Connect and a great ingredient for user delight.