Dynamic DNS is a service which allows you to alias a dynamic IP address to a static hostname in any of the domains, allowing your computer to be more easily accessed from any location on the Internet.
The Dynamic DNS service is ideal for a website whose IP address changes frequently. With dynamic DNS, your hostname will always point to a correct IP address, no matter how often your ISP changes it.
One known issue with Dynamic DNS is mail. Many providers block e-mail from a dynamic IP address. To solve this, you can relay all of your outgoing e-mail through your ISP's mail server. Simply set the SMTP/outgoing mail server in your e-mail client.
Below is a list of links to some Dynamic DNS service providers: