LJB: Davis never committed, and at least the other two didn't wait until NLOI day to pull a stupid-assed stunt.
Thanks for having my back, Nutty.
Davis did everything but commit... For months prior to Signing Day, he talked about how he was a Buckeye, how it would be great playing with D'Andrea, etc. He went so far as to recruit other players to OSU (a la Justin Zwick and Ryan Williams). When he didn't actually commit, he didn't get an LOI; when he didn't get an LOI on Signing Day, he whined and moaned and dropped OSU from consideration. (BTW, Davis' LOI went to Richard Washington, who also pulled a Signing Day switcheroo). That's why I said "Davis, sort of".
As Nutty correctly pointed out, McClover pulled an egregious Signing Day stunt, very offensive to OSU.
Dwayne Jarrett verballed to OSU on the eve (literally) of Signing Day, then hours later inked the LOI to USC.
EDIT: I might also add Durell Price, from L.A., who faxed his LOI to OSU upside down (essentially, he faxed a blank sheet of paper to the coaches - thus, his LOI was unofficial and non-binding). Later that day, he signed an LOI for UCLA, and went there instead. BTW, OSU got another Californian in his place, Na'il Diggs - not a bad trade, IMO.