Well, I'm going to throw this one out there again, since the topic of flat repair seems to come up pretty often.

If you see where the debris has caused the hole, it is often faster to patch than to replace the tube. The key is that you see the debris - glass, metal, thorn - and instead of taking off the wheel, just take off a 10" section of tire, pull out the tube, remove the offending object, slap a patch on that thing, put it back in, reseat the tire, pump and roll.

If you don't want to deal with glue, get pre-glued patches.