<< OK, I have a working trivial plugin for this that just does a 30bit int 
for now. >>

I do not understand what is different about working with 30 bit integers as 
opposed to the 32 bit version I started with?

<< Seems to work ok - making a bag of 1000 values suggests it at least does a 
tolerable job. Though it does bother me a bit that in a whole load of tests 
I've not seen any number with less than a half-dozen digits. I'll let you 
numerics fanatics worry about that part. >>

You mean that all of the sample numbers have at least six decimal digits?

<< So what sorts of values would be useful? Is just a 30bit int ok with any 
further cleverness being done in the image? >>

I am not sure if the desirable properties of the Mersenne Twister are 
preserved if we drop down from 32 bit words. I was hoping to duplicate the 
algorithm exactly. (Note I said "I", not "you" !) For casual use, it may not 
be any better or worse than the current generator. For serious use, though, 
it should reproduce the C program. If it does not, then one suspects that 
other properties are lost, too.

-Mark