Distributed login

I'm looking for a distributed login solution...

We've got several Solaris and Linux servers, and numerous Win2K workstations in a Win2K domain with ADS. Now, a single login for everything would be nice, but I'm not really expecting it. But, I would like to be able to cut the required logins down to two at most. (One for everything Windows related and one for everything *ix related.)

Any thoughts?