This collection started growing back in 2008 with a 4x4 that I got for Christmas. It grew from there to around 50 items as of 2 weeks ago (March 2010). Then I traveled to Hong Kong and acquired close to 100 new items for the collection, bringing it to its present total of approximately 150 items.
Follow up to the Rubik's cube, as shown by its name.
Produced in 1982 and 1983 by Ideal in Taiwan and Macau.
A 2x2x2 in shape of a tetrahedron.