Subway Ad 1

While not yet found in a subway, a Viacom site is currently hosting a subway poster/ad for Perplex City. This thread points to this MetaFilter post (by adrianhon, of all people), which in turn points to this site, which contains this ad.

The poster contains the four immediately visible puzzles as well as heiroglyphs in the background.

[Image:Mindcandy-perplexcity.jpg]