As for whether or not a person should resign, in a hopeless case between 2 serious opponents its probably a good idea. I agree with Dmitri however that between good friends ya do what you feel and even try the silly moves just to hack around, maybe even play with a bit of endgame for practise. Also agree GL is a polite way to begin, even if thats the last thing you mean as far as the eventual outcome of the game goes.