I've been trying to write monologues lately. It's not my forte, I like to work a lot of jokes or puns into sketches, and if you have two characters this is easy, but with one character, set-up followed by punchline comes off as contrived. It's amazing how much more difficult this is to write than stand-up, since straight-out jokes are expected when you're doing stand-up.
The world lost one of the great deliverers of monologues recently in Ronnie Barker. He had this great delivery of monologues, and I believe most of them were written by him and Barry Cryer. I'm trying to write a Ronnie Barkeresque monologue for a later Feral Chihuahuas show, here's a taste of what he could do.