Marissa "Con Gusto" Meizel's Open Mic Ranting definitely merits a look. I'm definitely all for a "tuning for longer than 30 seconds counts as a song" rule.
12. ACTING LIKE YOU KNOW WHAT YOU ARE DOING IS NOT THE SAME AS KNOWING WHAT YOU ARE DOING. ... I am talking about getting onstage, throwing a fit about the sound or your mic, or whatnot... and then being out of tune or off-key.
And remembering the last time I hosted a night, if you're one of the "hang out outside, run in for my set, then leave" types, damn right I'd remember you next week and slot you dead last. Maybe everyone should host an open mike for a few weeks, just to gain some perspective on what the horrible, mean ol' host is dealing with.