The good thing about the combo jack is that it works with the hundreds of 3.5mm phone headsets which a lot of people already carry. There is a wide range of these splitters available on the market, spanning a range of price and quality points. (newer Blackberry, iPhone, etc. headsets).
See comments below this article for additional customer tried / recommended splitters, or check the "Related Links" to the article to view the related forum discussions on this topic.