The Innovators Keep On Rolling: Google Gadgets/Muni/NextBus Mashup!
I tried it out and for what it does, it's remarkably simple. The app helps you figure out your transit stop ID# (courtesy of 511.org) and you're up and running. This sort of thing is useful if you have more than one option from your office or home, and want to quickly see which one is not enveloped in a failwhale delay when you're getting ready to leave.
Mr. Sohigian has also developed similar Google Gadget apps for Portland's TriMet system and the Chicago Transit Authority, and will roll out more for other cities in the future. If you have questions about it, you can find him on Twitter at the address listed above.