Luckily my normal rides are not as urban as some have to contend with. I started out commuting with flat strips and slime tubes and heavy tires, but the kind of flats I get (nails, staples, about once a year) tend to defeat those things so why have all that weight on the bike year-round only to have to fix flats anyway? Another advantage of my less-than-urban commute (I actually commute from one burb to an ever more remote burb) is that i tend to know where the glass sjhows up and accumulates and can anticipate and avoid it. Works for me.