"The Official Thermodynamics Fan Club of the UK." writes:
> p.s. I'm sure this is a common question, but I have many 3x3x3, and one
> 5x5x5, can I still get a 4x4x4 anywhere? would anyone consider selling one
> to me?

The last time I bought one was in 1993 in Tokyo (at Tokyu Hands
department store). I'll be visiting again soon and will check to see if
they still have any. This is the only place I've been able to find them,
outside of those who sell from their private collections. At this point I
don't think anyone has any available for sale though. If I find any in
Japan I'll certainly buy as many as possible and let the list know.

The 5x5x5 is more widely available, try:

Peter Beck
pbeck@pica.army.mil

or

Dr. Christoph Bandelow
An der Wabeck 37
58456 Witten
Germany

Good luck,

Dave Litwin