Berkeley Astronomy Colloquia:
http://astron.berkeley.edu/colloquia.html

Berkeley Physics Collloquia:
http://redesign.physics.berkeley.edu/cgi-bin/webcal/webcalcolloquia.pl

Stanford Physics Colloquia:
http://www.stanford.edu/dept/physics/events/ap_phys.html

The Center for Star Formation Studies:
http://www-space.arc.nasa.gov/~csf/

Other astronomy-related colloquia:

UC Santa Cruz Astronomy Dept. Colloquia:
http://astro.ucsc.edu/~dept/talks/