I always carry a plug kit and a air compressor, they don't take up very much room and will save you if you get a flat. I use a slime pump also but it was about $29.00, a different one than in the previous post and it works faster that that one. This is the one I have

I saw that one, and almost bought it, but then I saw the $10 one was a little smaller, had a built in gauge and a LED light, and thought either of those might prove useful some day.
When I brought it home, I tested it on both front and rear to add 5 or 6 PSI just to make sure it works, and it works OK on the front (under a minute), but took a long time to do the rear (more volume). Also, the LED does not light up the gauge, which seems stupid, and there's no off switch for the LED. It points out the bottom, so it's good for is seeing the hole in the tire, or where the valve stem is if you're working in the dark. A compact LED flashlight would do that just fine.
I might have to get the one you did if I ever use mine on the road and see it's an all day affair to fill the rear from clear flat.