I use clarkmoody in a minimized window with sound enabled so I can hear the up/down ticks.

Then I use a few windows of bitcoinity with the exchanges I am tracking. Bitcoinity has large text which is useful since I have a PC plugged into my TV and can just glance at it to easily track the prices. It's pretty useful when arbitrage opportunities show up.  I know bitcoinity has sound also but the downticks aren't loud enough.