The wife and I just use our real names, no last names needed. I thought it would be cool and fun to come up with aliases, like we're spies or something. Wife didn't like the idea because she was afraid she wouldn't remember what they were. Alas, no pretend name fun for us. But unless you have a very unique name or you give a last name, you'll just be one of the crowd.
And we usually forget peoples' name immediately, and just create nicknames for them anyways (for instance M & M becomes "eminems", the couple from Canada we referred to as "Saskatoon", a tall blonde gentleman we met became "Ivan Drago", etc.)