I have always believed in eating your own dog food (or sipping your own champagne, depending on how you look at it), so as a consultant with SharePoint as one of my specialities, I have always used the product a fair bit outside of work.
I used to run my personal website on SharePoint, mainly just for the heck of it. I have occasionally used team sites for organising trips and other social events. However most of this has now moved to Facebook because it relieves you of the cumbersome task of managing user credentials. I have used document workspaces for group assignments when I was still doing my MBA. When travelling I usually set up a secure document library with scanned copies of all my travel documents, so I can access them from anywhere if need be. And finally I currently have a few private wikis for developing various ideas and concepts with friends.
There are potentially a few scenarios in your personal life where you can take advantage of SharePoint as a productivity tool. The good news is that there are plenty of providers out there offering hosted SharePoint for a reasonable price (I use Webhost4life and WebCentral) or even for free (e.g. Frontpages Web Hosting).