Some people know how to do this already and some down but you can change the way the characters look for the fighting games and play online too,
I have writtin huge detailed tutorials over at VersusColors.com on how to do this and have support setup for any one that wants to try some games include
Marvel Super Heroes Vs Street Fighter
Marvel Vs Capcom
Marvel Vs Capcom 2
Marvel Super Heroes
Street Fighter Alpha 1 2 and 3
Super Gem Fighter
and 3rd strike
there are Hundreds of patches and more come out often along with tutorials and such so enjoy
Rules say no pics so you have to go see for yourself at
http://VersusColors.com/