Here's something I've found exceptionally neat, if not overly practical: An Ottawa Traffic Info Widget
for Dashboard. (OSX Tiger required, of course. Windows users and those still stuck at Panther can get something similar out of the Konfabulator widget
that seems to have inspired this port.)
Thanks to Dashboard's ability to use multiple copies of the same widget - and options, in that widget, to restrict the cycle of City traffic cameras to particular intersections - I can have multiple simultaneous views on Centretown, at places in the cycles synchronized to show multiple locations on the same block at once. (And the rest of the city, too, but who cares?) I feel so Big Brother-voyeuristic. (Less so, though, with the Parliament Hill webcam, updated only every five minutes, and too high up to see anything interesting, with the address merely plugged into similar widget SlothCam
It's not wholly impractical, though. Thanks to my apartment's position in the building, the direction my windows face, and my fear of opening them (don't ask, don't ask), I've never been able to actually tell if it's raining outside, or just cloudy. Dashboard finally lets me quickly determine that in near-real-time, before I head out the front door. Thanks, Tiger, for enabling both laziness and irrational phobias!
(Also: Panic Transmit + Accompanying Dashboard Widget = So Very Nifty. Dashboard is growing on me...)