I made a Google Transit widget a while back on iGoogle. This weekend I ported it to Netvibes:
The nice thing about this widget is that you set it up for your town (if Google Transit is supported there) and then it defaults to that city for searches. You can also set the default start or end addresses to give faster results. And it includes “by bike” directions for both Portland, OR and Milwaukee, WI (that is why I made the thing to begin with).