Julius Sridhar said:

>I don't think there will ever be a PDP-6 running UNIX, due to the rarity
>of the system.

I would say that finding a full-blown PDP 10 would be pretty hard to do 
these days. The Retrocomputing Museum of Rhode Island has one, but they
plan to run tops 10 or 20 on it. They were lucky, in that it had a complete
PM before it was put in storage. They plan to bring it up slowly to it's
full configuration, as they expect the costs for electricity and HVAC to
be quite high.

The last big user in the US was probably compuserve. 

There is/was a company in California that builds systems using modern parts
that runs PDP 10 software.
-- 
Rick Kelly  rmk@rmkhome.com  www.rmkhome.com