Where can I find a comprehensive list of the world's religions and
belief systems? Only the names.

Hello religioncurious:

The best list I've been able to find is at:

Classification of Entries - World Religions
URL: http://philtar.ucsm.ac.uk/encyclopedia/class.html

This list shows both those religions that have worldwide following, as
well as those that are strictly regional (at bottom of page).

I truly believe that is the best page you are going to get on the Web. 

Search Strategy (on Google):
* "world religions" 
(I then searched for sets of a few of the more obscure names off the
above list, but got no further pages.)

I hope this helps.

websearcher