For Undergraduates:
Paid Summer 2011 Undergrad Research Placements:
Over 400 programs - REU and Other Summer Research Opportunities for
Undergrads link)

For Financial Support in Graduate School Opportunities:
Bridges, GK-12, IGERT and NSF Grad Research Fellowship programs provide
generous stipend and tuition support for students through the National
Science Foundation: link)

For Postdoc opportunities: link)

For NASA-supported internships, fellowships and scholarships: link)