We always send out cards for Christmas. I have each of our children draw a nativity picture and then make the cards from those drawings. I search for religious Christmas poetry/songs to include inside and try to come up with some sort of greeting. I write a personal greeting in most of the cards, as well.
Of course, we also include the dreaded "Christmas letter" w/pictures of the kids and highlights from the last year--nothing braggy--just a few things the kids are doing or enjoy. We live far from family so, this is a way to connect--but I suppose the letter/no letter debate would be for another thread (I know it exists somewhere here ;) :p )
The price of stamps is certainly increasing, but I don't know that I could do much with what I would save on not sending cards. If you think about it, you stick a 44-cent stamp on an envelope and they will take it ANYWHERE in the US--it's still a bargain ;) (but don't tell the post office that, they'll raise rates again!) :D
An email or facebook is no exchange for a personalized card--at least for me. We love getting cards!