You can view activity in Enterprise Manager - IIRC you can expand the Management tab for a given server and you should see an option to View Activity or something like that (I don't have a SQL2000 box anymore so I can't look it up right now).

It will show you who is connected, what computer they are connected from, what database they are currently using, and the SQL command they are currently executing among other things.

You can set the process view window to automatically refresh.