When it comes to protecting a frame from possible damage when locking up, most people seem to go with some sort of hack that covers the frame. I for one wrapped my top tube with an old inner tube, and then accented it with some colorful tape - what most would call "horrid."
Others use old linoleum like was featured in a recent entry.
Here is one I came upon the other day that I had never seen before -
While I admire the thought, from my experience, as Duct tape wears the sticky substance can start to get all over stuff. If you wrapped this lock around your waste or any clothing, after a while I think the sticky residue might be all over the place.
Which also reminded me of another hack that is similar to the tape concept, but the corduroy would seem to be a far superior choice to Duct tape.
And finally, you can modify a chain/lock like the one I have that comes with a protective sleeve, but in this case the lock and links can rub holes in your clothing while riding. As I documented in an entry a while back, the leg of an old pair of jeans helps to prevent clothing damage if you wear your lock around your waist.