I've done this for a couple years now and my students have been very engaged and really enjoy it. I have also seen it on Pinterest as well...
My students have sticky notes that they keep in their book bags. They use them to stop and jot notes and stick them in the books as they are independently reading. As a class we come up with ways that they may react to a book and record them on a chart. We also come up with a sign or symbol to stand for it that they draw on the sticky note. The students then write their name on it if they'd like and stick it on the page. They really enjoy seeing how others have reacted to a story when they check out a new book from our class library... :)
And as we go through the year, if the students think of other ways to react to a story, we add it to the chart. For that purpose, I left a little bit of extra space on the chart...I just folded it under and paper-clipped it.
PS- I'm officially obsessed with sticky notes! I have a million sticky notes that parents have donated and I probably use them in half of my lessons...I just LOVE them! :)