I'm making a bit of a bold step this year and not celebrating it at all (and yes the missus supports that stance).
I have never been one for making a big fuss but I usually get some flowers or something.
I think Valentines day is cool, but I think it should be about telling someone you have worshipped from afar how you feel not about couples at all.
Hallmark and the like know that couples are better cash cows and as a result most singletons I know hate it when the day should be for them.
Though if you do want an excellent card without paying Hallmark these are fantastic: