Google Street View has sent people on bicycles around 30 major archaeological sites in Mexico, including Chichen Itza, Palenque, Monte Alban, Teotihuacan, Tulum, Cobá, and more. You can go right up to (but not up) the pyramids. For me, seeing the tourists and the souvenir vendors is part of the fun. Daniel Hernandez at the LA Times has some more good links.
Archaeologists from Mexico's National Institute of Anthropology and History have used a remote-controlled microcamera to explore a 1500-year-old sealed Mayan burial chamber at the Palenque archaeological site in Chiapas, Mexico. Story in English from the Guardian but be sure to click on "Fotos" at the first link.