My friends who are a couple (of about 4-5 years) have just jointly changed their surnames to 'Q'- after the name for the set of all rational numbers (they're computer scientists).

This is partly because they shun the institution of marriage but feel on some level that they should adopt a 'family name' that represents their status as a solid unit. They will now be known as Daniel Q and Claire Elizabeth Q.

any opinions thereon? stupid or sweet?

I think it's cool.