Working Amateur
Satellites
Low Earth Orbit Amateur Radio Satellites
There are dozens of low earth orbit amateur satellites that you can receive and the good news is that you don't need a license to do so. However, you need at least a technicians liscense to transmit and try to make contacts, which can be really challenging. But it's well worth it if you can stand outside with a 5 watt walkie-talkie (hams call them "handi-talkies" or HTs) and make a contact hundreds of miles away using overhead satellite repeaters (transponders). Of course, you can use your indoor or mobile station as well.
If you're interested in contacting the International Space Station, here's a tracker that may pique your curiousity:
Amsat Online Satellite Pass Predictions
There is a lot of information on the AMSAT North America (Radio Amateur Satellite Corporation) website that we won't reproduce here, but it's well worth a look at the AMSAT.ORG to learn more about what's happening on amateur satellite radio.
You'll note in the video that Wayne Steury is on his cheap Chinese Baofeng HT changing channels very quickly to keep up with the frequency shifting due to the Doppler Effect, the same phenomenon that makes train whistles change tone as they approach and then pass. It affects radio frequencies in the same way as they become compressed (higher frequency) as the satellite nears and elongated as the satellite becomes more distant (lower frequency). It's best to have a number of nearby receive frequencies programmed into your radio. You'll need to set up custom repeater shifts, as well since the statellite transponders don't use the standard repeater shifts as do terrestrial repeaters.