IPhoto users - What to do with unknown faces?

Ok, now that I have my shiny new iMac, I am importing my gabillion family photos into iPhoto. The faces feature is nothing short of brilliant. However, as I start building the library of faces of friends and family I am also getting a pretty hefty collection of unknown faces that appear in the background of many images.

This is a problem because as the number of unknown faces creeps up iPhoto will keep asking you about them as it tries to associate a name to the unknown face.

I’ve thought about creating a generic “person” named “Unknown” and just dumping them all in there, but I can’t help but wonder if this would hose up the recognition algorithm.

Is there a correct way to tell iPhoto that I don’t know this face, don’t ask me about it again?