Where several site offer building widgets for use in websites, sproutbuilder has built it's application on top of Adobes Flex. This could be one of the first sites that allow you to build applications in flash. The application is very wellbuilt, and the outcome is a clear result of that. The application reminds me of a general image viewer with the exception that you're not editing a picture, but creating a smart widget that looks professional.

There's all kinds of things that you can include in a Sprout now and features marked "coming soon" include Meebo chat, Ribbit VOIP and PollDaddy polls. ()

A worthy addition to my personal favorites.

Go and check it out. Sproutbuilder is currently in private beta, unfortunately. Maybe they allow my readers access?