Pansexual is attraction to all genders. Some pansexuals suggest that they are gender-blind; that gender and sex are insignificant or irrelevant in determining whether they will be sexually attracted to others. Pansexual doesn't mean that someone is sexually attracted to everyone (just as a heterosexual is not attracted to everyone of the opposite binary gender).
See also Edit
Pansexuality on LGBT info
Pansexuality on Sexuality Wiki
Pansexuality on Sexual Orientation Wiki
Pansexuality on wikipedia