i think it's a pool...
mining.bitcoin.cz
i initially tried that as the host, now i am trying api.bitcoin.cz which is also listed on that site. here's what's happening:
Starting DiabloMiner (GPU)...
-----------------------------
[9/16/11 4:21:17 PM] Started
[9/16/11 4:21:17 PM] Connecting to:
http://api.bitcoin.cz:8332/[9/16/11 4:21:19 PM] Added GeForce 8600M GT (#1) (4 CU, local work size of 256)
[9/16/11 4:21:25 PM] ERROR: Can't connect to Bitcoin: connect timed out
[9/16/11 4:21:30 PM] ERROR: Can't connect to Bitcoin: connect timed out
[9/16/11 4:21:35 PM] ERROR: Can't connect to Bitcoin: connect timed out
[9/16/11 4:21:35 PM] ERROR: Can't connect to Bitcoin: connect timed out
[9/16/11 4:21:40 PM] ERROR: Can't connect to Bitcoin: connect timed out
[9/16/11 4:21:45 PM] ERROR: Can't connect to Bitcoin: connect timed out
[9/16/11 4:21:45 PM] ERROR: Can't connect to Bitcoin: connect timed out
[9/16/11 4:21:52 PM] ERROR: Can't connect to Bitcoin: connect timed out
2767/3276 khash/sec