Whilst doing some R&D around Twitter related services I've noticed holes lacking in APIs for a number of services. It's not just myself that groans, support queues, mailing lists and Twitter are full of people grumbling about lacking functionality from the services.
Today it was the turn of photo hosting service Twitpic who provide a great basic API service but lacks any ability to extract all images for a specific user through the API. A minor bonus is that each user of the service gets an RSS feed of their uploaded images, although it only serves the last 20 images - 20 being the number of photos shown per page.