Yep. Direct & FFELP loans for "new borrowers" as of 10/01/1998 can be forgiven for qualified teachers at Title I (poverty) schools in certain subjects. Requires 5 years of teaching before it can be granted. $5,000 to $17,500 depending on subject area.
There are many other programs especially for public service that involve a government agency or private foundation paying on your student loans for you. Health & Human Services, VISTA, PeaceCorpse, Americorpse, DOD are some examples.
Perkins loans have additional cancellation options.
For more info on loan forgiveness:
http://www.finaid.org/loans/forgiveness.phtml