Lol @ Gimp = common person
Anyhow. GIMP is excellent, and it's free.... photoshop is much more awesome though.
However you can get Photoshop CS elements (or somthing similar) which basically has about the same features as GIMP (I think... I haven't got it myself) but I find PS easier to use.... and it's about £60 on Amazon (I assume maybe $80)
Personally I have the full school version of Photoshop as my tutor let me have the disc.... but first of all this was 7 years ago (about when I think Photoshop 8 or 9 was releasing) and second of all it's a school, which means outdated software.... as such I have PS 5.0 Which I think came out in 1996 or 1997 or something.