RFMacG:
"it gives you and I a way to..."
Nope. "It gives you and me a way to..." is correct.
As for who and whom, the grammar is simple: "who" is nominative (a subject), while "whom" is one of three types of object. It can be a direct object, as in "Whom did you see?"; it can be the object of a preposition, as in "From whom did she receive the camera?"; it can even be an indirect object ("Whom did you send the letter?") but this usage is awkward and rarely used in English, whether American or British, where "To whom did you send the letter?" is generally preferred.
But I always teach my students that the rules of grammar are transitory; usage will ultimately prevail. As the usage of "whom" steadily diminishes, the rules will fold under the will of the speakers of the language, becoming by turn arcane, then obscure, and ultimately, extinct. This is natural; it is the organic nature of language.
Because I teach German, I have to take care to let my students know that the rules governing the German equivalents of "who" and "whom" are still observed and that mistakes can truly change the meaning of of what they say or write. But German, like English, is subject to the same trend toward change, so I freely acknowledge that I may someday, in some circumstances, be teaching entirely different rules.
Tschüss!