There is one simple reason you should register your own domain name – a portable email address. I’ve used various email providers in the past but I’ve had the same email since 1999:
I haven’t had to update accounts with an ever changing email address and I never have to send out mass emails to people alerting them to a new address. While most people are using Gmail, it’s easy to forget that having an @yahoo.com address years ago meant that you were on the cutting edge of technology. Who’s to say that today’s @gmail.com will not end up being tomorrow’s @aol.com? Check out this fantastic cartoon from The Oatmeal for a good laugh.
Do yourself a favor and get a personal domain. It’s easy to do and quite inexpensive, especially if you use Google Apps. They will not only host your email for free, but can even help with domain name registration for a reasonable price.