The Sheldon Method works technically (yeah, it's really hard to cut through a rim), but it has a critical psychological flaw: It
looks like it shouldn't work. This may inspire casual thieves to attempt to pull the frame out from around the locked rear wheel, and to wreck the bike in frustration when it doesn't work. I see a lot of smashed-up frames and wheels U-locked to fences and posts; they've clearly been the victims of someone's fury.
Here in the Bay Area, stolen bicycles are one of the common, freely exchangeable forms of street currency (along with sex, drugs and stolen iPhones). I've seen the pickup truck/angle grinder guys pull up to locked bikes in downtown Berkeley in broad daylight, and take them in less than a minute right under the eyes of the public. The critical thing is not perfect protection; it's making your bike obviously less vulnerable that the bike locked up next to it.
I like the idea of Pitlocks, especially since I discovered that they make an all-threaded universal rear spindle that will work with rear hubs narrower than 130/135mm. But I'd still use a cable through the wheels, just to keep the thieves discouraged enough to focus on somebody else.
Peter Adler
from the land of year-round bike thieves
Berkeley, CA/USA