I'm looking for suggestions here...

I was thinking of an application where the user would enter a range of 
numbers to find primes in.  The script would break this range down into 
smaller ranges and use TaskMaster to send these tasks (finding primes 
withing the given subranges) to multiple client machines.  But that's not 
a real good demo since as the numbers in the ranges get larger the time it 
takes to test each number in the range goes way up (probably 
exponentially).  So I'm looking for a problem that's a bit more linear so 
that as you add more client machines it's obvious that the problem is 
solved faster. It should also be something pretty easy to understand (and 
program) since it's intended to be a demo.

Phil