Since converting to Vista and its sidebar, I've always missed something I had when I was using the Yahoo! Widget Engine on XP - the TV guide. It just isn't the same having a web browser window open with the TV guide up all the time, so I took it upon myself to create one, using the data from the nice people at the Australian Community-driven TV Guide.
More info available on the project page, no point repeating it here. Check it out - Vista Australian TV Guide Gadget.
Here's some nice pictures to make it worth your while 
UPDATE (31/08/2007): It seems that the Australian Community-driven TV Guide cache XML servers are down at the moment, as they look for and organise someone else to host it. It's in the works, but not sure how long it'll be. I'll post an update here when it's back up. In the mean time, the gadget is well, pretty useless.
UPDATE (1/9/2007): Looks like it's all fixed - the servers are back up, and I can get data again. If they go down again, you can download the gadget anyway, and it'll automatically keep trying daily to get data. Any downtime should be temporary only anyway - there's no suggestion of removing the XML service by the TV Guide guys; they're just reallocating servers.