Yeah, the instant patches (or pre-glued) are OK for a quick fix. But, I tried to keep it on (instead of actually gluing a patch on) and it ALWAYS failed. Sometimes it would last a week - sometimes months, but ALWAYS eventually failed. I've only had about 10% of the glued patches fail and it was probably due to crappy conditions when I was gluing it (rain, cold).

I agree with others here. #1 is spare tube. If that fails, then I will repair the flat on the road. Remember to always check for WHY the tire was punctured. You don't want to put a new tube in only to get a flat a few minutes later because a piece of glass was sticking through the tread.