I look forward to the day I have one.

New Rules for the New Economy: Since a relationship involves two members, investing in it, its value increases twice as fast as one's investment, 1998, by Kevin Kelly

If you shop a lot you will carry a "passport profile" based on the P3P protocol (or one similar) encased in your smart card or online in a browser. You exchange it with the vendor during a commercial transaction. The passport technology will help firms remember you as you teach them how to serve you and earn your favor.