I have known for a while now that there were hacks out there to let you run homebrew games for the Wii off of SD cards. What I had not realised was that, through this, it is possible to archive your Wii games on a USB hard drive (or memory stick) and run them from there.
Admittedly, to do this you have to mess around with your Wii a little (not in the screwdriver sense, but in the firmware sense) but the following page explains, step-by-step what you need to do to get it working. http://gwht.wikidot.com/usb-loader
I plucked up the courage to risk it tonight and after a bit of toing and froing from laptop to Wii with an SD card, I had installed and patched enough to run the Configurable USB Loader, and have stored a few of my games on a USB stick I had to hand.
The next step it to buy a more permanent device so that I can store my whole library of games...