Well, I spent a few of hours on this one, and I'm hoping that it will turn out to have been worth it. I used heavy cardstock, and "laminated" the pockets with packing tape; so I think it will last. I also have plans for using the same board for lower case flowers and "starts with" pictures. One thing I really like about it are the folding flaps on the sides that allow it to stand up on its own. (the backing was part of a big corrugated cardboard box)
I traced around a cookie cutter for the outline of the flowers, and glued them on to index cards.
The pockets were a little tricky for G to use at first, but then she got the hang of it. (having laminated the pockets made them slippery, and definitely helped though) You can see her clapping for herself- I think as much for figuring out how to put things on the board as much as for matching the right letters.
Any other ideas for ways to use the board (so that I can relax about having spent so much time on it)? :-)