[pbhjpbhj]

>Some non conventional computers [1][2] do exponential space in polynomial time.

For under $500 ...

[suppressingfire]

As a re-representation of the DNA computing work cited above, you can actually do exponential work in poly time using a photocopier.

EDIT: here's a link to a paper describing this approach: http://www.springerlink.com/content/j5213p8761224304/