Well, mint is handy for cold drinks of various sorts, but mostly I just rip it out of the ground and give it to a friend who doesn't have a garden but does love fresh mint. (And she's Jamaican, so - hmmm.)

I would have thought lemon balm was entirely useless, but apparently it can be put into the bath, as you'll see if you scroll down in the comments here. unlike mint it's not pretty when it goes to seed, though.