Most UK folk clubs tend to allow people up for floor spots between the guest's spots and the residents' bash. When I ran a club, if there were any performers who I didn't know, they were allowed one song or 5 mins - if they were OK, they'd get offered another song or sometimes more. We once had a terrible singer who sung one of his own songs which seemed to go on and on. "How long's he got left ?", whispered the singer (a regular) who was about to follow him. I looked at my watch and replied "About 45 seconds". I must have spoken too loudly because the audience started counting down "44, 43, 42 etc). The singer took the hint and terminated the song prematurely on zero.

When I'm booked for a a gig in a pub etc, I don't put another performer on without checking with the landlord (or whoever is paying me). The trouble is that it often seems to be one of their friends anyway. Ah well it's usually a good time to declare an interval.

I will lend my guitar to someone I know (mind you very few people who know my guitar seem to want to borrow it .....), but very rarely to strangers. I work on the basis that most reasonable guitarists wouldn't go out without their box in the first pace ! Mind you, Bert Weedon's borrowed my old Yamaha on two oacasions.