Thanks to this thread, I realized last night that I've been carrying the wrong tubes for the past month (since I was forced to replace my commuter with a new commuter) -- Old bike had shrader valves, so I bought shrader tubes as backups. New bike has prestas. Perhaps I could squeeze the shraders through the rim, but I'm glad I haven't had a flat to have to find out. I suppose I'd have managed with the roadside patch. As I think on it, I'd better get some new tire levers for the on-bike repair kit, too...(though I can usually manage without if necessary).

There's one Bell at the local WalMart that comes with a plastic Presta adapter, and none of the others have anything, unless maybe one of the floor pumps has something similar wrapped up in its label. Even the Bell foot pump they carry has nothing for Prestas.

I wish there were presta Tireflys!

I've been running both for ~a year. Same reason as above - have a few presta tubes to burn thru, but haven't had any flats to speak of (knocks on wood), so haven't drilled it out - yet...

I have both on my bike. My Trek 520 came (used) with the original helicomatic rear hub, and when the cogs wore out it wasn't possible to replace them, and I wasn't keen on getting a new wider hub and having to bend my rear stays out to fit it, so for the time being I borrowed the rear wheel from my previous commuter - an old Japanese 10 speed. It has the same width of hub, but the rim is drilled for schrader, not presta.