I do not like pre-paid tuition plans.
ESAs and 529 savings plans are sound options. Some details of the latter vary by state.
You might find some good information by visiting these links:
http://www.collegeboard.com/student/...it-up/395.html
http://www.savingforcollege.com/
Also, specific to your state (PA) there is something called a TAP 529. You may want to look into it.
http://www.lfg.com/LincolnPageServer...pa5/index.html
http://www.bankrate.com/brm/saving4c....asp?planid=88