145.800: Worldwide downlink for voice and packet
145.200: Region 1 voice uplink (Europe, Central Asia and Africa)
144.490: Region 2 and 3 voice uplink (The Americas, and the Pacific)
145.990: Worldwide packet uplink
437.800: Repeater uplink
I found these frequencies @
http://hamradio.arc.nasa.gov/
Which has more things there than I could shake a stick at.