There is a better way to do that. Use dyndns.org for your dns, and then update the IP address whenever you want to. dyndns.org is free, and I used to use them. Then I found dnsmadeeasy.com, and I use them for all of my DNS stuff (crazy reliable, all around the world), and as a side bonus, I can offer my web hosting customers dynamic DNS for their home computers, which they can update with their own password. I realize this is starting to sound like an advertisement, but I have used dns made easy for four or five years now, and have been 100% thrilled with the services they provide. They doubled their prices a couple years ago, but they are still the best deal around.