Here is something fun I found, the Acme Candy Heart Maker. You can make your own Valentine candy hearts and email them or whatever. The only downside is you can only have 4 letters per line and 2 lines. Still, you can be creative. Here are a couple of mine:

Cryptogram has another candy heart making program that lets you enter more letters and lines but the hearts don't look like the real candy. Nonetheless, still fun.