I just finished grad school and found that letting people know up front worked very well for me. Any time I had to introduce myself or give a presentation I advertised it. By addressing it openly you take the stigma down a couple notches. If you stutter in an introduction, saying something like 'I do have a stutter, in case you haven't figured it out yet.' A little laugh takes a huge amount of pressure off you and them as well. The less it seems like a deal to you, the less it will be a deal for them.