i am moving to philadelphia (well, Bryn Mawr to be exact) next week and am trying to figure out what to get in terms of locks/etc. i have a fixed gear vintage trek that is worth about $300, the most expensive component being the velocity wheelset followed by the SLR saddle (which I have chained to a stay). i rode in London for several years, but always parked my bike in a private garage so i am relatively new to the urban locking scene. while i will probably spend a lot of time around bryn mawr, i intend to get around on my bike (ie downtown)

how safe is downtown philly (or bryn mawr for that matter)? is a mini u lock going to be enough for roaming about town? what do you philly riders use?