Your own, or other people's.
I'll try to remember some of my own, but I'll start with Col's story.
My mate Col lent someone else a pair of lovely Campagnolo wheels with deeep sections for a TT.
The someone else had a puncture, but his only tubes had short valves.
Was his solution:
a) buy more tubes (approximate cost £5)
2) buy a valve extender (approximate cost £2)
iii) chop a section out of the rim to fit the valve (approximate cost - one friendship)
Yep, he really mutilated that wheel, then returned it to Col - i've seen it in Col's workshop as he can't bear just to hoy it out