A lot of people, especially those on my friends-list, use "me" when in fact "I" would be correct.
As I was explaining to das_dingsi up there, a lot of English speakers don't know what the rule is and just use whichever one "sounds better"; it's a fairly common mistake.
This is also one example of cases still existing in English; Ennglish-speakers learning German always complain about having to learn then and try to say that we don't have this in English, but we do have some leftover bits of what used to be cases like what German has. Ours are just less obvious because the dative and accusative sort of got combined somewhere along the way, and also because English has no grammatical gender (and so you don't have to decline any articles or anything like that.) I actually made a post about this once; it should be around here somewhere...