This Posterous service looks like a great thing.
The picture attached is the ratio of the volume of a hyperball to its
circumscribing hypercube in N dimensions.
The mathematical relation is actually \frac{V_b}{V_c}(N)=\frac{\pi^\frac{N}{2}}{2^N \Gamma(\frac{N}{2}+1)}.
I need to review both the relation and the latex text as I am writing
from memory, but this should be good enough for a test post.