As lending out tools has been mentioned in the same breath as lending out bikes in this thread I'd like to recount something that happened to me today.
I've just today got round to starting work on an H.R. Morris frame that I acquired earlier in the year. I decided to fit a Baylis Wiley bottom bracket but found the fixed cup wouldn't even begin to thread in. So I had a look to see how much a bb tap would set me back. The Park Tool version is $790 and the locally made Hozan a heart-stopping $1000.
There's an LBS that I know but wasn't sure they'd have a BSC size tap so after getting some bread in a nearby shop called in to check before taking the frame in. It's a shop I've been using for around 10 years for control cables and the like and once got a call from them to ask me how to get a cotter pin out, as they know I like old bikes. That was actually on my wedding day. I'm on pretty good terms with them.
I went in and asked if they had the tool and the owner got their Hozan out, saying, 'What, do you want to use it?'. Very surprised indeed I said, 'What? Do you mean I can borrow it?' and he said, 'Yeah, we wouldn't usually but as it's you, that's fine.'
I took it home and tapped the threads (dead easy - it was just paint as the frame hasn't been built up since it was re-enamelled about 10 years ago), then thoroughly cleaned the tool and took it back, together with some beer as a thank you present.
All is well in this small part of the world.