My husband's last name (you know, the one I used to use here) is not that common in the US, or so we thought. It is more common in Canada. Well, one time he went to pick up his rental car somewhere, in Texas and they said, "Oh you have 2 reservations." There was another person, with same first, last, and middle initial renting a car at the same place. But he couldn't stick around to meet the guy. Now he has found out that 2-3 others in the US have the exact same name because they have emailed him.
My birth name is not super uncommon, but it is spelled differently than most of the people who have it. One time, I went to apply for a very small loan to finish grad school and I was turned down because of bad credit. So I went to the credit bureau in Phoenix and found out that they had my parents' 300.00 Sears bill on my credit report. My dad's name is Robert, similar to mine and the first 3 numbers of our SSNs are the same (very different from the ones in AZ, which all begin with 5 or 6). They wouldn't remove the mistake until my dad went down there and threatened lawsuit...