Thanks to US Senator Russ Feingold (and several other co-sponsors), an interesting piece of legislation was reintroduced and referred to Committee last week. Senate Bill 589 authorizes a new Global Service Fellowship to help rebuild citizen diplomacy, and to facilitate volunteerism among US professionals.
This Bill was introduced in 2007 and again in 2008. For more background on this idea, see this Brookings paper, and for a review of Sen. Feingold's opening remarks, see this post on the Working World blog.
The Bill is supported by the Building Bridges Coalition. Check them out if you're interested in international volunteer work.