Idea: Domain name exchange... trade your unused domains for other ones that might be of more value to you. Like baseball cards... but for domain names Somebody go develop it now.
truth be told thats the exact reason I held on to most of these, but with the birth of my second daughter and moving to the bay area for me it was a case of priorities.
I envisioned a mobile app with some kind of a simple barter system. I'd love to be part of a project working on it and can share some ideas I had sketched out.