I heard a guy on talk radio talking to a caller who claimed to be a Frisbeetarian. I had never heard of this religion I wondered if it is Christian or some obscure ancient pagan form of religion. Does anyone here know what their main beliefs might be and how they compare to mainstream churches?
Frisbeetarianism is a parody religion, along the same lines as Pastafarianism. It is sometimes attributed to comedian George Carlin:
Frisbeetarianism is the belief that when you die, your soul goes up on the roof and gets stuck. (source)
It's also attributed to comedian Jim Stafford in 1975.
In answer to your question then, no, it's not a form of Christianity nor a form of ancient paganism. It's simply a parody, created by comedians, to poke fun at religion.