Security

When I take my bike for quick errands I use the "integrated rear wheel lock" and a "chain lock" to secure my bike. If I had to leave it for long time, I'll throw in another U-lock in the mix.

I also have the old "bicycle chain in a inner tube" trick for the saddle. I would also cover the saddle with a plastic bag to hide and "ugly-fy" it a bit if I was gonna leave it locked for a long time.

A professional bike thief will still be able to take the bike or saddle.  The best I can hope for is to slow them down, or make them look for an easier target.

UPDATED APRIL 3, 2011:  I decided to remove some security features.