My layout is currently being expanded to make a complete 96ft loop around the upstairs train room/master bedroom. Going through my wifes closet. Tunneling into the dead space behind the stairway. Through my closet and then behind the bed. (My wife is the best!!) 
I didn't want to use Fastrack in these hidden areas. Since O-27 tubular is alot cheaper. So continuing with the cost saving, I decided to make my own transition pieces from info that forum member Flash wrote about in a post last April 2012.
Thanks Flash.
Cut a 10" Fastrack piece in half.
I was too lazy to use the hand saw. So the power saw melted the plastic some. 
For O-27 track. I used a 3/32 bit to drill out the U channel support.
The track is a good fit. I will still add power jumpers to ensure good power flow.
A closer view of the drilled out U channel supports.
