Not to go against CNC or anything, but for the particular picture you posted this looks like a good job for simple miter bench and drill press stop jigs. I may be looking at it wrong, but It seems like it would take longer to set the job up on the Bot than to cut the pipes to length and drill holes.
On a similar note, there is a part that I have been recently asked if I could mill on my Bot. It uses 2" solid round plastic stock and a .75" dado needs to be cut the entire length of the stock about 1" deep. I have come up with a hold down jig in my mind consisting of 2 beveled runners riding slightly on top of the stock (for horizontally and down pressure) that you could slide the stock in one end, mill, and slide out when done. That's the best I can come up with right now on holding round pipe to machine.
2006 PRTalpha 96x48
3hp SEV spindle
Vcarve Pro8
Always eager to consume large amounts of info, tips, and techniques!