I wouldn't mind leaving BOINC running 24/7. My fans aren't very loud at full speed, but it's still very noticable at night. Instead of changing the CPU settings in the morning and night, what if BOINC Manager added "Quiet Hours?" These quiet hours could be a user-specified time to use less CPU than normal. For instance, during quiet hours run on half the cores or half the CPU time instead of 100%.

Would anybody else use something like this? I think it's a good idea, but I'd like to know what other users think. :)