I got my belly button pierced last week. So far, I really really love it. Pain was about a 4/10, but lasted for roughly two seconds and then was over, and the healing process has been really smooth so far (though only a week in, it's hard to say, navel piercings are temperamental and prone to rejection).
I honestly wish more guys would do this. I don't even see it as a symbol of gayness that it's often perceived to be, it's a really nice looking piercing that I think would suit most guys. But unfortunately it's heavily feminized in society which is a real shame.
Might post a pic later, undecided.