R4.5 includes the new Team Monitor utility, which lets you kill teams graphically without using a third-party utility. Hit Ctrl-Alt-Del once, and all running teams will be listed (the old Vulcan Death Grip still works, however).
Application teams are listed in black, BeOS system teams are listed in blue, and misbehaving teams are listed in red. Select any team and click Kill to put a mischevious team out of its misery. Note that this tool only lets you kill entire teams, not individual threads. If you need that level of control, you might prefer a utility like ProcessController.
WARNING: Hitting Ctrl-Alt-Del more than once will invoke a hardware reset.