Thanks all! Unfortunately Walmart is the hardest to get to, since it's across the bay - hence across the Bay Bridge, which is a major PITA. There's a Lowes near my favorite pet store, and I need feeder mice and cat/dog food anyway... so I'll get my butt over there later, after I go back to sleep for a while.
Btw, will aluminum tape hold down the probe securely? Is that what you all use?