My bike has 700x28 tires. They're the skinniest tires I've ever had; they're beefy enough to take commuting without trouble, but there was a learning curve - right when I first got it, I had a run of flats. I took it to shops twice after the first flat and had THEM change it for me, and both times the tire was flat as a pancake an hour later. Nobody had bothered to check the inside of the tire.

I was frustrated enough the second time around that while I was at the shop I bought the tools I'd need to change the tire myself. An inexpensive floor pump, tire levers, a couple spare tubes. I was glad - by the time I got home the tire was flat. I pulled up Sheldon Brown's website and followed his instructions and found and removed the foriegn object (a staple!) myself. It wasn't hard, but I did get a little greasy.

Right now that same bike is sitting upside down with no rear wheel. I was in an accident and have to replace it - and I'm strongly considering a wheelset that will take x25s. Why not, now that I know how to change a flat?