Amazing Bike Lawn Mowers, article by Warren McLaren on Treehugger. Too funny. I believe that when I saw one of these in some old friends yard ( you know who you are), it was called, A Redneck Lawnmower.
How to Choose the Best John Deere Lawn Riding Mowers
Xtreme Mower Mayhem - Monster Mowers - A guide for the garage hobbiest. Fabrication and improvements which covers Enduro, ARMA and Monster Mower builds. This includes small engine rebuild and various mower upgrades.