I used a really simple system for many years. A plastic coated cable and padlock. That cable was just long enough to go around my waist twice. Clip the padlock into the cable and a belt loop and it was completely secure. Every cable I've ever seen since was either too long or too short to do that with.
Yes, I had no illusion that it was theft-proof. But for a quick lockup to a sign securing both wheels, it worked. Now when I held a job in Boston, I went to a motorcycle dealer and bought a real cable lock and just left that at work. 8-10 pounds? It wasn't light!
Edit: that cable lock went on a few tours.
Ben