How about having LimeWire detect whether someone's computer has been idle for a while (5 to 10 minutes) and base the hashing speed on that? When the computer is actively in use by the user, slowdown the hashing speed so the user wouldn't notice a major slowdown when using other apps on their machine, but when the computer has been idle for 5 to 10 minutes, ramp up the hashing speed to full speed. When the user comes back and starts using their computer again, slow the hashing speed down again so it wouldn't affect the performance of other programs running.