Yes.... as a matter of fact, quite a few of my coworkers know that I belly dance, and some have viewed my pics. It hasn't been a problem for me. Some have expressed an interest in coming to see me perform, and a couple have even expressed an interest in taking some classes(although, as far as I know, this has not taken place).
As far as the "sexy nurse" stereotype, I don't really feel like I've been stereotyped. I'm really comfortable talking with my coworkers(women and men, too) about my performances, costumes, etc. I think as long as you maintain professionalism and perform your work to the best of your ability, people will continue to respect you.
I feel you though when you said you weren't comfortable dancing at the interns graduation party. That's a situation that could get a little "tricky". You know how people talk!
I once had a student nurse that asked me to show her some "moves" when I mentioned that I belly dance. I kinda laughed it off. I mean, I'm not getting ready to belly dance at the nurses station.LOL

Some of my co-workers know & think it's cool...some of them want to learn too.... I shy away from 'showing' any 'moves' to them at work....They know I'm conservative and know that I only do appropriate events and respect taht I keep that aspect personally. No one seems to raise an eyebrow or two...
I did however do a quick dance to my favorite nurse in one of the unit's breakroom where we were having a potluck going away party - it was all women until I saw out of the corner of my eye the doc that I was just speaking with in the ER about facilitating a new mode on the ventilator, suggesting chest tubes, etc. - he was watching with a "entertainingly amused look on his face" I just thought, "great....how will he take me professionally with my RT stuff when he will now have visions of me in a belly-dance outfit??" Maybe it wasn't the best judgment, but I will never do that again.