From Women.com, some sage advice on how to survive if you wake up next to someone whose name you don’t remember:
1. Evidence of your partner’s name exists somewhere nearby. Your task will be to find it before he awakens, or before he starts any sort of meaningful conversation.
2. Get up and go to the bathroom.
The bathroom is a normal place to visit first thing in the morning, and it is also a place where you might discover his name.
3. Look through the medicine cabinet for prescription medicines with his name on the label.
This is why it’s always advisable–unless you think you’ve found your true love–not to sleep over. Sadly, this has never happened to me. I expect it will once I become an addled octogenarian, but that’s not really the same thing, is it? Has this ever happened to you? How’d that work out for you?
DarrenBarefoot.com 
I had a guy sleep over once… we hadn’t been intimate (thanks to a last-minute, half-sober judgement call I made for the better) but when I woke up, damn if I could remember his name. I think my half-sober self is quite wise, sometimes. Fortunately it was my house, so I simply pleaded a complete lack of breakfast food and he headed for the hills, never to be seen again.