I've had the pleasure of traveling to several archaeological sites with experts -- not just informed tour guides, but with the people doing groundbreaking research at these very sites. In 2012, a host of organizations is offering this opportunity to anyone with a few thousand dollars burning a hole in their pocket waiting for a once-in-a-lifetime travel opportunity.
One of these is the www.mayaexploration.org , a nonprofit organization based in Austin, Texas, dedicated to the study of ancient Maya civilization. MEC offers regular courses for travelers, a lecture series, and education programs for students, teachers, and the general public. They have two special trips planned for 2012. I list the details of these trips here on this page about multi-country 2012 tours . I particularly love the idea behind archaeologist Dr. Edwin Barnhart's "Surfing the Zenith in the Maya World: Zenith Passage 2012 Tour" (8 days, Aug. 5–15, 2012, $3,100 per person) in which the group actually follows the solar zenith (when the sun is exactly overhead, the date changes with latitude) from site to site.
Dr. Barnhart has also developed the best Maya calendar converter and iPhone app .