I received an e-mail today from Continental Airlines regarding discount fares to Mexico, Belize and the Caribbean. Of course, there are limitations, purchase 3 days in advance, stay a Saturday and complete travel by June 13th. If I read the ad right this is a round trip fare. The link to the page is included after the fare information.
Houston, TX (IAH) Belize City, Belize (BZE) $213 http://www.continental.com/dash/build_dash.asp?vs_2002_05_15_00