got robbed yesterday, bought a kryptonite today (because if this bike gets stolen, i can't get anywhere). I wish i'd bought the kryptonite yesterday ... you're going to have to buy a fatty lock eventually, so if you've got the scratch, it's better to do it now.
oh, if i'd only listened.

Yam - that bites! I'm so sorry your bike was stolen! Thieves just stink!! Merry, merry, right?
Please look in the packaging of your new lock and sign up for the anti-theft protection offer (I'm assuming you got a u-lock or chain), just in case, and register your keys with us online for free.
Again, really, really sorry.....

Helvetica - please listen to the folks that have replied to you. A cable is not recommended for any urban area, including San Fran. While it is certainly better than nothing, a high end u-lock or chain is your best bet. Also, no matter which brand you go with, make sure to lock your bike properly. That is a big part of keeping your bike and its parts safe.

Happy Holidays to you all.

I'd like to hear Kryptonite Lock discuss the differences between his product and OnGuard locks.

Well, you don't need to ask Kryptonite. Soldsecure.com and the ART Foundation, and Cycling Plus all publish test results for the best locks. No surprises in the tests. Heavy, expensive U-locks test very well. Cables test poorly. Put a "gold" rated lock around your rear wheel. Attach the front wheel to the frame with a light weight "silver" rated lock. Your bike won't be going anywhere.

www.soldsecure.com/leisure.htm