I need a source of stackable tiles. If you have ever seen the tiles from the game "Upwords", they are exactly what I am looking for. Unfortunately, this game is fairly hard to find in thrift shops or online at any reasonable price.
An Image of these tiles is here:
http://when-is-now.com/image.axd?picture=2009%2F9%2FScrabble4.jpg
The tiles are squares of plastic with a hollow bottom so that they will lock onto the board, or each other, very loosely.....easy to pick up and remove, unlike, for example, the "Lego" toys.
This isn't just piling up; these are shaped so that they interlock; the tops fit into the bottoms of the one above, and so on.
I don't care what the material is, so long as they are durable and cheap.
Any ideas of sources?