1. Update web.xml
In ColdFusion (e.g. #CFUSIONROOT#\wwwroot\WEB-INF\web.xml in windows or under JRUn on a Mac, in /Applications/JRun4/servers/cfusion/cfusion-ear/cfusion-war/WEB-INF/web.xml) add the following xml:
Note that the 14 and 15 should be unique (and I make them sequential - I *think* that matters) so if you have 9 mappings, these would be _10 and _11.
Then Restart CF.
2. Update Web Server
In IIS6, go into site properties, click on the "home directory" tab, click on the configure button, under mappings, select and "edit" the .cfm record and copy the value of "executable". Cancel out of that, Add new mapping, paste the executable value, put ".html" into the extension and hit OK (leave as all verbs).
In Apache 2.x on a Mac (should be same elsewhere) I went into httpd.conf. I found a line that said AddHandler jrun-handler .jsp .jws .cfm .cfml .cfc .cfr .cfswf (search for .cfm). I added .html to the end of the list giving:
AddHandler jrun-handler .jsp .jws .cfm .cfml .cfc .cfr .cfswf .html
I then restarted Apache (in Terminal sudo apachectl restart - enter root password when requested).
Tested and working.