A couple of weeks ago I deployed my first intranet application for home. If your not familiar, an intranet application is just a website that you cannot get to generally on the web unless you have specific credentials. I was combing through my documents one afternoon and realized that I had a ton of little text files with notes on them. Things like information on my cable modem and home network to reminders about trips I'd like to take.
It dawned on me that this is just screaming for a Wiki. So I deployed OpenWiki in a restricted website that is only accessible in our house with the right authentication. I was able to better organize information and move a lot of other information onto it, like what is our contract number with the plumbing people.
Pretty fun. I named the site Spiral. The idea being that it is a big spiral notebook for all in the house to share.