In answer to the anonymous poster, a Mac widget is a tiny little programme which runs within the Mac's Dashboard programme.
There are hundreds of widgets to download that cover anything from aviation weather to amino acid tables (I feel my life is complete with this). You'll wonder how you ever managed before without the Prezzi Benzina, to check the average price of Benzine in Italy. It's a marvel.
One of my most useful ones is Tubetrack, despite its' name, it doesn't just give you up to the minute times of London's wonderful underground system, it also covers UK national rail, DLR and Dublin DART and as well. I have mine set up for Plumstead train times, so I can see which train I'll miss because I'm messing about on the computer.
It's not all useful/useless information though, here's one if you're a sudoku addict, and a webcam of Halifax, no not the bank opposite Yates Wine Lodge in Lewisham, this is Halifax in Nova Scotia, Canada.