I lock my bike up wherever I go in SF. I use an oversized on-guard u-lock with a cable through the rear wheel (just because you don't have a QR on your rear wheel doesn't make it safe). My U-lock has more than it's share of saw/cable cutter marks on it. I got a new set of marks this week @ city hall. Fricken city hall!!! What's next church (I don't go... BUT IF I DID!)???