Other than a hole I spontaneously got near the valve stem (this happened 30 minutes AFTER arriving at work, too... must've finally just given way) - I've always patched.. But for times on the road, I carry a spare to swap out straight away and patch at my destination/home that night as others have mentioned.

For patching, I use a couple of different kits I got from the LBS, nothing fancy. I scrub with sandpaper (after using a Sharpie to correctly identify the problem area if it's not obvious), apply glue, let it go off, put the patch on and then put my u-lock on the patch end-on to apply some heavy-ish pressure on the patch and leave it overnight typically. I have a good 8 spares for my roadie and a couple of 26" spares. With tubes being around $2 at MEC, I pick up a couple if I go there to buy anything usually, mainly because I like to have the compact/rolled up tubes convenience to carry as spares (I can never seem to roll them up quite how they come in the box).

I carry a presta/schrader adaptor in case I can use a gas station pump to fill up, otherwise I'll hand-crank it on my frame pump to about ~70PSI which is LOW, but enough to get me home/to a subway station (as I carry spare fare in my kit in case "it" happens). I've had to change a pinch flat at 3:30am this summer... so I know my ideas work in practicality.

ax0n reminded me of a tube I blew up and it got caught in the rim/tyre pinch and blew itself apart two minutes after inflation (poor fitting/check on my part ) - I keep that tube around for patch material - but chain cover is a great idea - thanks!