Recently (past month) got a tattoo on my forearm, after thinking about getting one for more than a year. Day 1 of getting it, I regretted it and kept staring at it. Day 2 onwards, it started growing on me. Now, I really like it! And sometimes I fret that it should have been more visible. I even forget its there and when ever I happen to glance at it, I break into a big smile.
I don't think my tattoo is going to have any adverse effect on my profession/career. In fact, I think I will benefit because of it. Also, the thing is, if my work is good, people will not care two hoots that I have a small tattoo on my forearm. Just like no one has ever given a shit that I wear a diamond nose pin (for last 15 years), and I've worked in the corporate consulting sector where days reserved for client meetings had a very strict dress code. Its all about how you carry yourself. And actually if some of these things are 'you', I've noticed that they have a way of blending with your personality, that they almost become invisible. I've noticed that with myself and with quite a few others. And just in case some department somewhere does not hire me because I have a tattoo, and decides to overlook my research because of that, well then, they are sending me a huge signal - that I need to run away from them super fast! This is a good case where self-selection is beneficial to both parties.
Ofcourse, now, if you go and get a skull or something tattooed on your entire arm.. now, thats a different matter. Subtlety and professionalism is most definitely possible in the tattoo world.
I wish you good luck with your experience