My Internet connection was really annoying this morning; things took forever and timed out more often than not. Pulling the DSL plug and plugging it back in (so the modem would re-sync the connection) helped briefly but not for long.
This evening, things hadn't gone back to normal, so I decided to pull the power cable from the DSL modem, wait five seconds, and put it back in. Once it had reconnected, things appeared to work fine. So yay!
Now I don't have to go and see who's the culprit (Vista? cable? router? phone line? ISP?).