Monk without being Lawful

[Shin Okada]

One of the easiest and non-arguable way to increase unarmed attack damages is, to take 4 levels of fighter and take Improve Unarmed Strike, Weapon Focus (Unarmed Strike) & Weapon Specialization (Unarmed Strike). Then buy some good magic gauntlet.

 

[Sylrae]

One of the easiest and non-arguable way to increase unarmed attack damages is, to take 4 levels of fighter and take Improve Unarmed Strike, Weapon Focus (Unarmed Strike) & Weapon Specialization (Unarmed Strike). Then buy some good magic gauntlet.

there is a chaos monk class that was detailed in dragon mag. I believe you can find it at crystalkeep.
Crystal Keep - D&D and d20 System

 

[Voadam]

I forget if Beyond Monks by Chainmail Bikini games requires lawfulness for their full BAB monk alternative the martial artist.

I think there is a prestige class in Libris Equitis Compiled by E.N. Publishing called the dirty monk that is a non lawful dirty fighting style monk alternative.

Neither are official WotC but are designed for 3e under the OGL.

 

[dystmesis]

Change your alignment to lawful. Take a level of monk. Then put your alignment back to chaotic or whatever. Task complete. Seriously, alignment doesn't matter in the slighest, I don't see why people even bother.

 

[Dragonwriter]

Change your alignment to lawful. Take a level of monk. Then put your alignment back to chaotic or whatever. Task complete. Seriously, alignment doesn't matter in the slighest, I don't see why people even bother.

The entire point of alignment is that it is your character's outlook. It doesn't just change overnight. It's like saying "I love chocolate" one day and the next screaming about how chocolate is evil and should not exist. It just doesn't happen, short of magic.

That said, creating a character above 1st level and making them ex-monk is possible. Really, the simplest way for a chaotic person to be good at hand-to-hand fighting is through Imp. Unarmed Strike and maybe going Reaping Mauler (PrC from CW, I think they are non-lawful).
(I can't comment on the PrCs mentioned by other posters since I don't know/don't have them available to me.)

 

[Herzog]

In my (my groups) opinion, there are several points where alignment matters:

1. As a guideline for roleplaying your character. Large deviations could be a reason for the DM to suggest changing the alignment of the character. However, an aligment chosen at character creation should be seen an intention of roleplay, and keeping that alignment should be encouraged unless in-game situations have influenced the character to a point that he starts to behave differently.
2. As a strict guideline for roleplaying your character when an aligment is forced upon you. This is the case when a helmet of opposite alignment comes into play, or when you are temporarily playing an NPC. (for instance, when your character has been possessed, or replaced with a doppleganger)
3. When you want to change your alignment. If, for whatever reason, you want to change your alignment, the new alignment should fit your characters' actions. If not, the alignment hasn't changed at all (or maybe to a different alignment). It should of course be possible to get into a Monk class at some point, but in our opinion that alignment change shouldn't come easy, and as stated above, our group doesn't think the player in question can pull it off.

Of course, there are several playstyles less heavy on the roleplaying aspect where Alignment is just another stat. As there are retraining rules for Feats, skills, and spells, you could in a similar manner change your alignment.
I'm not saying that is badwrongfun, it's just not our way of playing...