I normally ride with two new inner tubes so that if I get any punctures I just whip out the old and replace with the new (after locating the cause of the puncture, of course!).
However, after years of doing this I now have a nice collection of inner tubes hanging up in the garage which I always say that I'm gonna repair and re-use at some stage. I'm happy to get them patched and re-use them, but I'm not too sure how to carry them around with me so that I don't accidentally create a puncture whilst they're in my pocket. Any suggestions on how this can be acheived, or is there such a thing as a inner tube recycle centre for disposal?
Another thing, when do you say that you're tyres need to be replaced? My tyres (Michelin Axial Pro's) look new and the the rubber is still reasonably thick, however where I've had to remove bits of glass from them, I now have a few 3mm cracks in them. They're not noticeably visible, and in fact I have to search hard to find them, but is it time to replace them when a few splits/cracks appear or do I have a few miles in them yet?