Right now Ebates has some double cash back deals for St. Valentines.
A selection of the double Cash back rates are :
drugstore.com = 12%
Blue Nile = 5%
FTD florist = 20%
teleflora.com = 20%
Godiva chocolate = 8%
Lancome = 14%
To get the cash back you have to sign up at Ebates and then use a link from Ebates to visit the merchant before you purchase.
The only merchant on that list that I've ever used is drugstore.com. 12% back at drugstore.com seems like it has the potential for some pretty good bargains. I'm not exactly sure what drugstore.com has to do with St. Valentines but I won't argue.
Personally I've found the major florist services to be pretty pricey. But if you use them then 20% back is certainly worth doing.