> I'd like to see a Drb-based store, so that you could have the speed of
> memory-based access along with the ability to have a dedicated session
> server for seamless failover of webservers behind a hardware load
> balancer.

It's already there! ;)

Have a look in vendor/actionpack/cgi_ext -- there's both a server and a 
client (Session store). Works great too and it's pretty fast.
--
David Heinemeier Hansson,
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