To listen to FreePartyRadio.CoM on your G1, first you need to install the "StreamFurious" application which can be found in the android market within the G1.
Once this is installed on your phone, use your normal internet browser and type in www.freepartyradio.com/radio.pls and hit enter, you should then be directed back to the StreamFurious application where the preperation of the station begins, wait for it to load up, and the radio should start playing!
As with all ways of streaming, make sure you don't have a data limit, as radio streaming takes up quite some bandwith!