On Thu, 13 Dec 2012 14:16:44 -0600, Leon lcb11211@swbelldotnet
With the top bearing flush trim bit you get a perfect cut along your
guide whether you rotate the router or not and you do not have to deal
with a bushing.

I use something like this,

http://www.amazon.com/Freud-50-102-2...flush+trim+bit

And, the Lee Valley version
http://www.leevalley.com/en/Wood/pag...435,46171&ap=1