I carry the NY STD lock routinely, on my Thorn Nomad. It's a plenty expensive bike that I would really hate to lose! It's also a big heavy bike. So I need a decently big lock even with the Sheldon Brown method that I use - just to get around the rim + tire + fender. And the weight of the lock doesn't add so so much to the steel frame and my BMI 25 flab. Yeah and all the maps and tools etc. that I routinely carry too.

I carry the lock in my Carradice SuperC seat bag which is mounted with the SQR thingy. There are some nifty bags that are SQR-specific e.g. the Trax - http://www.peterwhitecycles.com/carradice.asp - should have plenty of room for the lock.