> if so take a lvl as psion or psychic warrior
I assumed the original poster wanted a pure Monk, perhaps he could clarify this?
I did consider taking a level or two of Rogue, thinking that the Sneak Attack damage and the tons of Skills would complement the Monks strengths nicely. I looked at a Monk3/Rogue2 and a Monk4/Rogue1. The latter worked out pretty well, but I decided to stay with Monk5 since it seemed un-Monkly to suddenly become interested in Rogue levels.
> I wouldn't mind seeing Gizzard and Christian's figures...
I dont have S&F; can you summarize their table? I'm not sure I grok it.
Anyway, my thought process was just for Monks with 1 basic attack, since thats what I am.

This should hold you 'til 8th level or so though. I started by trying to calculate my average damage per round. That is either:
regular damage = reg hit chance * avg dmg or:
flurry damage = flurry chance * avg dmg + flurry chance * avg dmg which becomes:
flurry damage = (2 * flurry chance) * avg dmg
So basically, if (2 * flurry chance) > (regular chance) then you are hitting more. So lets run some sample numbers (with my average damage of (1+8)/2 +2 = 6.5):
Need to roll 11 to hit:
Regular = 50% * 6.5 = 3.25
Flurry = (2 * 40%) * 6.5 = 5.2
Need 16 to hit:
Regular = 25% * 6.5 = 1.625
Flurry = (2 * 15%) * 6.5 = 1.95
Need 18 to hit:
Regular = 15% * 6.5 = .975 <- winner!
Flurry = (2 * 5%) * 6.5 = .65
Need 19 to hit:
Regular = 10% * 6.5 = .65 <-tie
Flurry = (2 * 5%) * 6.5 = .65
Need 20 to hit:
Regular = 5% * 6.5 = .325
Flurry = (2 * 5%) * 6.5 = .65 <- winner!
You can see from these examples how things get weird as the Flurry starts to auto-hit on a 20 despite the -2 penalty. After I've written this all out, I realize that the to-hit chance calculations are correct, but that to consider damage I really have to consider the criticals. I'll go through that tomorrow I think, but tonite I am too sleepy! ;-)
Still, it isnt going to change the idea that its not a "flurry of misses", you actually do hit more with the Flurry than not (except at 18).
The calculations incidentally highlight the fact that the Monk is not a big-time damage machine like the Fighter or Barbarian. I think our partys Barbarian would be shamed forever if he ever did only 5.2 points in a round to a lightly armored target.