I throw a couple of those cool looking UAL dark blue lap blankets over my rack and TT at night or when not in use. I still leave all SS stuff turned on -- just keep the back of the rack open toward the wall. That's the simple solution (along w/ an occasional light dusting with a feather duster or a Billy Bags black lamb's wool AudioDuster ;--)
Sbanks idea is good but replacement HEPA filters are very expensive and the device is only effective if you keep the room well sealed -- so getting dust-free ventilation is a problem.
One good solution (actually two) for your whole house if you have forced air heating/cooling is electostatic filters. There are powered ones, permanently installed in the main supply duct which you wipe off occasionally -- expensive but IMO can save thousands of dollars in health care costs, especially if anyone has allergies. The second is a passive (non-powered) washable electrostatic filter that replaces the fiberglas ones you (are supposed to) replace every month ;--) These are my favorite for a retrofit situation and cost about $100 for a 1 ft x 2 ft unit, but they are made to fit any size. Here's a 20 x 20 on amazon for fifty bucks: http://www.amazon.com/20x24x1-EZ-2000-Electrostatic-Washable-Filter/dp/B0006VSYQA
