Do you correspond with anyone the old fashioned way? (You know where you sit down with a pen and paper and actually write a card or letter.) I know it's something not many of us do anymore. My grandmother is one of the only people I write to on a semi regular basis. She is wonderful at sending us cards and short letters througout the year. I love hearing from her and reading her thoughtful and well-written notes. I try to write back each time and spend a few minutes composing a letter of sorts. What's written in the card is obviously the most important thing, but it's always nice when the card itself is beautiful. One place that always has fabulous stationary is Papyrus.
I'm such a sucker for this kind of thing. You can order from Papyrus online and I'm quite sure Target carries some of their cards as well.
Etsy is also a great source for all kinds of paper products and pretty notecards.