Like qwertyuiopasdfghjklzxcvbnm, but with the top row of numbers and symbols.
Dan: I'm bored.
Harry: Then just qwertyuiopasdfghjklzxcvbnm.
Dan: But I've done that already.
Harry: Have you tried `1234567890-=?
Dan: *gasp* No, I haven't! I gotta try it.
This is when you absent-mindedly run your finger along the keys, left to right, then right to left... Being careful not to press delete, enter or tab. The phenomena usually occurrs when you are so bored you really don't know what else to do...