On Fri, 20 May 2011 13:20:13 -0700 (PDT), gcotterl
wrote:

What is a quick and easy way to cut 5/8" thick rubber tiles made from
recycled car tires?

(I have about 60 tiles to cut. A utility knife will take forever).

http://envirotile.ca/envirotile.html suggests the use of either a break-tip
knife or a sabre saw. A good[*] sabre saw would be my choice for 60 tiles. A
circular saw with a fence might work well, too.
[*] crappy ones can't cut straight even if you wanted a wavy edge.