For the last eight months (eight? has it really been that long?) I have been working on a book that shows how to use a new site: zembly.com. I am really excited about the project and have had great fun (fun? yes, creating is very fun) building widgets and social applications. The book will be available first on Safari Rough Cuts and then in traditional print form. If you sign up on zembly, you can read the tutorial chapter right now (zembly Basics). (zembly is still in private beta, which means you need an invitation to check it out. You can get an invitation below.)
What is zembly? zembly is a social programming site that lets you build (and host!) applications for Facebook, Meebo, OpenSocial (such as Orkut and MySpace). zembly also makes it easy to build services, widgets, and web applications for the iPhone. I have embedded 2 example widgets on my blog (look on the right side bar). The flickr slide show widget randomly displays my flickr photos with titles and the mlb scores widget gives you today’s baseball scores. Both were built and are hosted on zembly (and are featured examples in the book).
One of my favorite widgets lets you plan a journey on the London Tube. The widget is built with data from tubeplanner.com extracted with dapper, then finally a mashup on zembly brings in Google maps. Try it out.
You can view the widget and see how it's built on zembly here (after you sign up).
Do you have an iPhone? Here is an iPhone-friendly version of the London Tube widget.