I have owned several domains for some time, and I seem to be accumulating them (slightly).
When I started (I can't remember exactly when that was), I only had one. Then I bought a second one that pointed to the first.
Now, I have five. And I haven't gotten much further than I was when I had two.
At this point, I have the two that pretty much point to the same place - a web site hosted on someone else's servers. And a third that is pointing to email - hosted on someone else's servers.
Since I now have 'extra' domains, I can afford to try setting one up to do the things that I am paying others for now (web and email hosting). Also, if I am hosting my own web sites, then I will be able to take advantage of languages and hosting environments that I would be unwilling to pay extra for (JavaEE, etc).
And, I have a computer that spends all of its time turned on doing nothing hooked up to a broadband internet connection.
Hopefully, before Monday rolls back around, I will have at least a functioning test for my own web and mail host running.