I don't want to belabor this point too much, because McCain would have to be a massive hypocrite to bring it up*, but I thought it was worth noting:

[T]he Illinois Planned Parenthood Council says Obama's "present" votes were actually part of a careful strategy to prevent those restrictions from passing.

President Pam Sutherland said the group feared several senators were going to vote "yes" on the legislation because of attacks from Republicans over their past opposition. Sutherland says she approached Obama and convinced him to vote "present" so that the wavering senators would do the same. For their purposes, a "present" was as good as an outright "no" because it kept the bills from reaching the majority needed to pass.

* So expect it any day now.