It can be frustrating to keep your long list of contact information constantly up-to-date, which is precisely why Plaxo.com was developed. Plaxo lets you import all of your contacts into their web-based interface. You also provide Plaxo with all of your current information, which it keeps stored in your profile. When one of your contacts is using Plaxo as well, and they change their contact information, the information is automatically updated in your Plaxo contact list. Likewise, anytime you change your contact information, you only have to change it once on Plaxo, and your information will be updated in everybody who has you in their address book. People who aren't using Plaxo will receive a nice email informing them that your contact information has changed.