"7/5/00 - Per Matt's suggestion, I've gone ahead and (quickly) thrown together The Leaky Cauldron, a weblog dedicated to the further film and book adventures of Harry Potter. Check it out and, if you'd like to become a contributor, drop me a line."
Kevin was using Blogger at the time and his site was on Geocities before it moved to his own domain.
It took a little research once I heard news that Yahoo! had decided to kill the GeoCities site off to determine the first URL to The Leaky Cauldron, before I moved it over to my personal site at http://www.brain-stream.com and then to http://www.the-leaky-cauldron.org (where it resides today -yes, you can blame me for the dashes and full words).
That URL was:
http://www.geocities.com/kevincmurphy/potterblog.html
An original placeholder of the site still exists at Kevin's domain forwarding people over to the main site.
So there's another piece of Potter Fandom History for those who didn't know.