I got an Abus lock For my bike I have 2 with me, the Link lock folds and goes in a pouch
http://www.jbimporters.com/web/check...t_number=39370

the Armored cable lock hangs from the bars , and I carry a loop end cable
then I can secure both wheels and the frame to a fixed object..

needing to tool up for several different types of locks is a handicap for the miscreants.