I wouldn't get a tattoo in a place you can't easily cover for an interview. Once you're hired, your employer can't discriminate against you for having a tattoo (its part of your appearance) unless it shows something obscene. My tattoo is on my upper shin, so while its pretty easily visible under a knee length skirt or summer dress/cardigan combo, when I've gone for interviews I just wear black slack pants and it's all covered over.

My boss actually loves my tattoo now that she's seen it. Go figure. Get something tasteful and it can provide a great talking point!