The trick with mashing up with the web is that it's actually not very easy or very intuitive. That's why people like Adrian Holovaty are so brilliant: they make it look so easy.
The lack of ease-of-use has, however, created a gulf between those that get it (those fluent in dozens of different APIs) and the rest of us. Well Mozilla (that's the Firefox people) just built a bridge across that gulf:
Ubiquity for Firefox from Aza Raskin on Vimeo.
Will this do to the programmable web what Blogger and Wordpress did to publishing--finally democratize it and make it ubiquitous? Clearly, when you name a piece of software "Ubiquity" you hope the answer is a resounding YES.