Frank is like this. He just gets so excited to be somewhere new and around new people or dogs. I just keep his harness and leash on so we can roam around together, but it still takes him such a long time to settle down. Usually it is the worst when there are kids or other dogs. He just loves them so much and wants to be involved in everything.
I do the leash thing when there is too much stimulation. Helps to keep them focused.