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

Berkeley Physics Collloquia:
http://www.physics.berkeley.edu/events/options.php?type=All

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/