I have some of the re-usable kind that have a little release latch. I have used those to lash onto my baggage just about anything from a rain coat to a part that fell off my bike. The part was not crucial to performance, so I just elected to lash it on and fix it at home.
hmmm..lets see, I know of someone who broke his rear der and lashed a short length of PVC pipe to his chain stay. By running the chain through it, it acted as a sort of chain tensioner.
There are literally thousands of uses, this ought to be an interesting thread.