As it turns out, half (at least) of my recent connectivity complaints can be traced to a denial of service attack on my ISP over the last week. On Tuesday, I was essentially dead to the wired world–I was checking my mail from my WAP phone, for God's sake.
That's the third time I've lost connectivity because of a DOS in the last six months. The first two were from Code Red-related zombie attacks that forced my ISP to shut down its Covad DSL customers and bring them back one by one until they found the zombie machines inside the Covad net. This one appears to have been entirely external, but still totally hosed the DSL net again.
As if I don't have enough to worry about with Covad. At least I'm not an @Home customer…