If you like vintage valentines you should check out the Vintage Valentine Museum. Jolene has set it all up just for fun and has no problem with people borrowing images for websites and personal use, but only asks that you use your own bandwidth and give credit back to the site. She does also have a shop here.
The museum has a nice collection of cutesy ones and some oddball ones I have never seen before. I like the Native American ones.
And this one is one of the strangest old Valentines I have ever seen. Circa 1930.