I see two basic options: you acknowledge it outright or you don't. There are pros and cons to both. If you acknowledge, you're opening up discussion with the interviewer that you are aware you stutter, and it's no longer the elephant in the room. You can use this to your advantage when asked those "tell me about a difficult time" questions if you've had one related to your stutter that you overcame. Show why it makes you better. If you don't, that's your choice too. You're going in just as any another applicant, and there's no chance of someone saying you played the pity card. (That'd be poopy if they did, but some might.) Go in knowing you might stutter, but it will not be the end of the world. You've worked before, and you'll work again. Best of luck to you!