somea puzzles
The pieces of this puzzle can be put together to form a cube  it is called the Soma Cube. Here is a page that shows the 7 parts that make up the soma cube in 3D.
You can buy the wooden version of this shown here from themathszone shop (along with lots of other nice maths things). I am planning on making some big ones of these. I was inspired by the site momath.org which has pictures of some people solving a giant soma puzzle and other fun looking activities... (follow this link to find out about some more truly amazing activities from momath.org). 
Here is a short video of one of my year 7 students completing it!
There are lots of other shapes you can make with the soma pieces... 

Through the momath website I also found out about the puzzle tetraxis, shown below. I have one and would like to get some more for the students!
Thanks to Jane Kostick for being so helpful in discussing the tetraxis; she tells me they are not making any more because the cost of magnets has increased so dramatically this year! She sent me this is a really interesting description of the geometry behind the tetraxis.