No, I don't unload them. I use machines with at least 1GB of RAM instead. As for disconnected, it doesn't apply, since I manually get/checkout/checkin everything. For me, that's more natural, since I don't want to inadvertently check out a file and not realise that I have to put it back, and generally the documentation standard I'm working to (varies from client to client) requires that I list changed files and/or label checkpoints, as well as using check-in comments.
Steve S Developer for hire