Hi, storrao.
I'm not sure I did anything to fix it, and I wouldn't be surprised if it popped up again.
I did the usual... turn it off, turn it on, run disk check, run permission check.
It hasn't reoccured yet, and I'm running the same apps I always run. I don't tax the system heavily and I shut down my apps when I'm not using them.
I am keeping a Finder window open to the virtual memory folder now, but so far, it has not budged. There's one file there that is 67MB is size.
I guess if I started to see a huge increase in the number and size of files there, then I will examine which apps are using up the resources and maybe find the one that's leaking. Although, I'm not entirely convinced that any of them are leaking since I've seen weird things with Mac OS X over the years and wouldn't disqualify this being a bug.
I agree with what Kevin said (above), but IMHO, there is no excuse for an OS to allow itself to get to the point where the user is completely locked out and has to power off the system. (This has happened to me on Linux servers and has happened frequently on windoze which I rarely us any more, so I'm not picking on Mac OS X, I'm picking on all OS's that have this issue -- and my old roommate would say "Then, write your own OS!")