I got the first few without any help, but then it started getting harder and I took advantage of a few online resources, listed below in order of utility.
Ad art’s list of logos (PDF)
Mint’s fast food page
Yahoo’s list of fast food restaurants
Wikipedia’s list of fast food restaurants
Dane Golden’s illusions of candor
Free dictionary’s list of restaurant chains
The one thing I don’t understand is why in the world would anyone pay $1 to get an answer? I mean really, it’s just a game.