I can remember back in the early days of Linux when we were doing this against Matrox cards, as they pulled the same stunt as nVidia. At least nVidia does put some drivers on their website that you can hack around with to get your card working with your respective kernel.
I remember having to plop down $99 on a commercial X-Server (back in '95) and it wasn't a memorable experience....
Oh well, I'll stop complaining now!