Easy Reputation Increase  -  To quickly and easily increase your rep, simply run into a wall. Every time you do this, the game will give you +1 to your rep.

Go to the status menu then the change name screen and put in a code in bold below

Get $999999.99 - PLAYA
Custom Move - XTRA2
Custom Character - XTRA0
Custom Self - XTRA1
Fill Stats - DAMAX
Erase Save Data - ERAZE

Get Phoenix Wing, Inlines, Springlines, Rocketeers, Air Merc's, Narcishoes, Magic Pants, Pandora Box, Skaterz, Custom Fit - WUZZY

Get Mach Punch, Dragon Kick, Acro Circus, Grand Slam, Javelin Man, Slick Trick, Nitro Port, Twin Kick, Deadly Shot, Top Spin, Helicopter, Torpedo - WAZZA

Get Boomerang, Charge It, Bat Bang, Flying Kick, Speed Drop, Bomb Blow, Killer Kick, Bike Kick, Slam Punk, Dragon Knee, God Fist, Hyper Guard - DAMAX

Get Slap Happy, Pulper, Headbutt, Kickstand, Big Bang, Wheel Throw, Glide Chop, Head Bomb, Chain Kick, Jet Kick, Shuriken, Flip Throw - FUZZY

Get Members in Posse  -  Do the following to get each member in your posse:

Ted: When Rex offer's to join you decline him then leave. Come back and beat everyone there and you will find Ted
Turk: Have a high reputation
Thor: Have a high reputation when you 1st fight him
Rick: Start the game as Ryan and go to Sherman park
Mojo: Have a high reputation
Jesse: Have a high reputation and beat turk five times
Tex: Get a good reputation and have Ivan on your team

Unlockable Character's and Events  -  Get This By Doing This

Meet Todo Must have a reputation of either equal or higher to getting Kobayashi unto your team, he is located at the 2nd shopping place in the game

Meet Todo Second Time Must have meet him the first time and this time he appears at Reihou's gate after you beat Gouda once

Get Kobayashi on Your Team Must have high reputation the 1st time you fight him
Get Mochizuki Have High Reputation
Get Taira Have High Reputation
Get Kumada Decline Himada's offer to join you and come back and fight everyone and Kumada will be there
Fight Riki/Kunio Start the game in 1 player mode only not 2 player mode and go outside the 2nd factory and you will fight your ally
Get Gouda Talk to the girl before the spa, then the girl outside the fish store, then at the 1st place of the last shopping place
Get Godai Have Gouda in your team and a good reputation
Get Maeda Play as Riki only in the beginning and go to Sherman Park
Get Sugata Play in 1 player mode as Kunio then he will be either at the beginning place or at Sherman Park when Kinoshita appears there
Get Sonokwa and the Senridai Bombers Play as 1 player without Riki and beat the Senridai Bombers anywhere 3 times then go to the 2nd place in the game and beat everyone there

Fight Slick with the Dragon Twins and Onizuka Must have 3 allies that are not Mochizuki,Taira,or Kinoshita

Get Hayasaka Beat Mochizuki 5 times and Hayasaka will appear(requires high reputation for him to join you)

Fight the Dragon Twins with Gouda Joining You Without any Enemies in the Beginning When Gouda asks to join you, say no and go meet Godai and say yes to his question, then go to Reihou High's last floor
Fight Alex/Ryan Start the game in Solo mode and when you exit the second factory, you will meet Ryan, say 'YES' and then you will fight.
Fight Slick with the Dragon Twins and Otis You must have 3 allies in your posse that are not Turk, Mojo and Blade
Fight the Dragon Twins with Ivan Joining you without any enemies in the beginning When Ivan asks to join your posse, say 'NO' and go meet Tex and say 'YES' to his question, then head to RC High's last floor.

Have Tex join your posse Have Ivan in your team and have a good reputation
Have Ivan join your posse Talk to the girl before the spa, then the girl outside the fish store, then at the 1st place of the last shopping place
Have Jesse join your posse Beat Turk 5 times and Jesse will appear (requires high reputation for him to join you)
Have Thor join your posse Must have high reputation the first time you fight him
Have Ted join your posse Decline Rex's offer to join and leave the area, come back to where Rex was, beat everyone up, and then you shall meet Ted
Have Rick join your posse Start the game as Ryan in Solo Mode and go to Sherman Park, Rick will be waiting and say 'YES' to his offer
Have Turk join your posse Have high reputation
Have Conan and the Generic Dudes join your posse Start the game in Solo mode and defeat the Generic Dudes anywhere 3 times and then go to the second place in the game and beat everyone up there
Have Gary join your posse Play in 1 player mode as Alex then he will be either at the beginning place or at Sherman Park when Blade appears there
Have Mojo join your posse Have high reputation

Meet Titus Must have a reputation of either equal or higher to getting Thor unto your team, he is located at the 2nd shopping place in the game
Meet Titus for the second time Must have meet him the first time and this time he appears at RC High's gate after you beat Ivan once

Boss locations

Boss 1: Moose
Sticksville-2nd Street, two screen east of the Grotto Mall.
Boss 2: Benny and Clyde
Riverside Park, one screen north of Capitol Ave. Bridge (very hard to find. right when you enter Capitol Ave. Bridge, go up)
Boss 3: Rocko
Inside WSL Co. Ware house, one screen north and one screen east of the Bike Trail Entrance.
Boss 4: Blade
Sherman Park, one screen north of Sticksville- Park Dr.
Boss 5: Turk
WSL Co. Entrance, one screen east of the Armstrong Thru-way.
Boss 6: Mojo
Empty Lot, north of the WSL Co. Entrance
Boss 7: Thor
3rd wheel factory
Boss 8: Ivan
Gates of school

(Note 1: If you save and turn off your GBA, you'll have to re-fight all the bosses, all it saves is your techniques, name, and money
Note 2: After you beat all the bosses, you get to teach a class on the infliction of pain!)

Easy Money  -  One way to make easy money is to let your partner fight the enemy gang members by himself and you walk behind him and pick up the money. Its fast easy way to make money. Spend all of your money on Bagels, or CDs they upgrade your stats the most.

Lots of Money$ & Merlin's Mystery Shop  -  Each time you defeat an enemy, he will drop money. To earn lots of money fast, purchase the expensive Aero Circus magazine at a book store fo $300. Its pricey but well worth it. Head for the Oak Hills mall and find Benny and Clyde somewhere around there. Use Aero Circus to defeat them again and again for fast cash (Note: There is also a spa here, just press up under the Chinese letters). To find Merlin's Mystery Shop, go to the Armstrong Thru-way. Walk along the wall and press up along the fourth and fifth lights. Items you buy there can boost your stats or lower them, so it would be wise to save before spending your money there.