I was surprised to discover that these charming little items are actually kitchen sponges! Found them in a pint-sized homewares & stationary shop in Helsinki called Pino Oy. Made by Form & Design, and, as you might be able to see from the tag, only €2.50 a pop!
[update: just discovered that red.house has also blogged about this company and its designer, ulrika elofsson. take a look!]