O T: Dog stands and barks in other dogs' faces @ Dog Park - how to control it?

[Jerry®]

My girl Tinker (a 15lbs Westie mix) is a very happy dog and loves other dogs to the point of getting so excited she'll stand and bark/talk at them instead of running and playing - well, she DOES run and romp but she's more of a referee. I can sense the other dog owners at the Dog Park are a bit annoyed by her continuous conversations, so I'm trying to learn how to at least command her to stop barking. She's not yapping - she's not showing agression - she just is really excited. She's 7 years old and very smart. I just don't want her to be so vocal and I'm NOT going to put a shock collar on her.

Any ideas?