I like to put out various centers in our Activity Room to keep it fresh. They aren't out all of the time. I saw this idea somewhere (don't remember where) and created my own.
I made a heart shape in Microsoft Publisher and added "I love my library because..." I printed the shape onto pink paper and cut them out. Kids are encouraged to add what they want and put them in the mailbox.
I am a big proponent of signage for our centers so parents can see what we are doing. After all, we're not just putting these hearts out to fill time.
If the Valentine's are legible, I hang them up above the center. As always with a station like this, you will get a stack of scribbles. They are still working on their writing skills, but I am not going to display them.
As an added bonus, these are great P.R. for your library. I have a feeling that many of these will be posted on our Twitter page for fun over the next week.