We have a Wii too. I've "hot-rodded" ours to use an external drive loaded with about 300 games. Instead of the normal interface you get when the Wii starts up, it loads some 3rd party homebrew code that allows us to flip through the available titles quickly and launch them without messing about with discs
The modding was fairly easy to do since I am a technical kind of guy, but I did have to spend several hours researching the whole thing so I could *know* what I was doing and not mess the whole thing up.
If you're interested in doing the same, a Google search for "Wii softmod" will get you started. I also found lots of good information, advice, and guides at the
WiiHacks.com forums.