Longtime readers of Maximum PC might remember a $500 build-off challenge several years pitting then Senior Editor (and now Deputy Editor) Gordon Mah Ung against former Associate Editor David Murphy. The build-off is memorable because Murphy neglected to factor in a case, choosing instead to house his components in a cardboard box. So yes, it can be done and you can skip a case if you really, really want to (and don't expect a visit from the fire marshal). Otherwise, have a look at today's top deal for a Corsair Carbide Series 500R Black ATX Mid-Tower Case for $80 with free shipping (normally $110 - use coupon code: [EMCPHHW57]; additional $20 mail-in-rebate). It has USB 3.0 ports, side air ducts, a multi-channel fan controller, and best of all a price tag that isn't too much higher than a fancy cardboard box!