This is the current favourite activity in our house, and it is so cheap and easy to set up. All you need is a load of pom poms (these are from Amazon but you can pick them up in most craft shops) and a couple of containers. We are using an empty plastic tub to store them in, and then a plastic bottle to post them into.
After a couple of minutes watching me do this activity, N was hooked and will happily sit down putting in pom after pom until the bottle is full. Then we shake them all out and start again.
I've been using this as an opportunity to introduce the concepts of 'in' and 'out'. Every time one of us puts a pom in the bottle, I say 'in!'. Given the number of poms that can fit in the bottle, that is a lot of repetition - but hearing language frequently is key to acquiring new words. Nate has been playing this game for a few days now, and occasionally I hear his little voice chiming 'in!' from across the room.
I've been doing the same for when we empty them out, repeating the word 'out' as well as modelling 'all gone' or 'finished' when the bottle is empty.
Since we started this activity I have noticed that N is beginning to demonstrate his understanding of 'in' across a range of different contexts - and this has an added bonus for me! He is now helping me to tidy things up as he can understand when I ask him to put things away e.g. 'in the box' or 'in the cupboard.'
Provided they don't all get lost (already they seem to be vanishing under furniture or winding up inside other toys) I have future plans for these poms! I am thinking of something involving colour sorting....but that is another post for another day.