Yes, it's definitely the Cerne Abbas Giant who has the giant cock
Got a picture somewhere of me and friends sitting in the giant cock, as a teen, and a scar on my leg from climbing over the barbed wire fence to get there, still visible (just), 30 years later!
Actually, do you know what, this summer is exactly the 30th anniversary of me sitting on the Cerne Abbas Giant's cock, could even be this very day. Sorry, probably not of interest to anyone else, but I wouldn't have realised that were it not for this thread. Perhaps it's a sign?! 
(Disclaimer, you're not really supposed to sit on it - ancient site and all that).
Shame, though, really as I'm much nearer the Long Man of Wilmington.