Another DNS option is Google's. You can put 8.8.8.8 and 8.8.4.4 as your two DNS servers to use them. I've been using them for a while now, much better than using my default ISPs servers (roadrunner/twc).
This made me curious so I checked -- working fine for met too. If previously given suggestions don't clear it up, it's probably ISP issue as Gordon suggested. If you have a laptop with Wifi you might try going to the parking lot of the nearest McDonald's and see if you can hit Parallax from their hotspot.
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http://code.google.com/speed/public-dns/
Funky stuff.