just bought it and am looking for any and all tips/tricks. thanks

you gotta be a bit more specific...

check out the gallery for '03 gixxers to get a feel of what you want.

Appearance?
Engine Performance?
Suspension?
Brakes?
etc...

what do you have in mind? skies the limit! You know the saying
"SPEED COST MONEY HOW FAST YOU WANNA GO !!! "

Speed DOES cost money (lots of), its more cost effective just to get rid of the 6 and buy a Gixxer 1K if it is really speed you are after.

Bling/handling bits - that is different, depends on what you want.

1st mod would be to fit a TRE - to get rid of the snatchy throttle response in the lower gears - not make it any faster - but a lot smoother.

Have to agree with Gixx6r you defo need a TRE on that bike. I put one on my K3 and the difference was great. Then you gotta deal with the ugly back end. Undertray will sort that. Those are the first things I would do.