Houston Street 1-2 stop, Manhattan.
Deborah Brown's "Platform Diving" mosaics are some of my favorite bits of subway art. More photos at nycsubway.org.

A correction: The new mosaic in the Times Square station, seen here on 2.22, is actually by Jack Beal and has something to do with Greek mythology.

See also 2.8.2001 and NYCMTA: Art en Route.

Oh no, another New York photo weblog thing: slower.net. (It's good.)