Is that the new Boomerang U-Lock made by OI! Catch-THIS-CagerTM.
I know what you mean Wes.... I leave mine at the office locked to the rack...

a... it's big and heavy
b.. I'm afraid I might use it.

I kinda like the visual OHNOYOUDON'T deterrent of the giant furgitaboutit chain.
Now to figure out a way of fixing it to my bag.