I commute in downtown Boston. My bike gets to stay in my office while I'm working, so it's not out on the street for hours and hours. It gets locked up all kinds of places around town, though, because I frequently stop off to do errands, get coffee, eat dinner, whatever. I have a krypto U-lock that's about eight years old, and sometimes I take a Krypto cable for use when there's nothing I can lock it to with the U-lock. My bike is a built-from-donated-parts hybrid that I bought from Bikes Not Bombs, it's awesomely functional but a long long way from shiny and spendy, and I don't leave easily-removed stuff on it when I lock the bike (like bike comp, lights, etc.). I don't bother to remove the seat though.