I've always invisioned creating my own affiliate script, as it isn't that much work (or at least as far as I can see). I would actually like to build one for free if someone can give me a front-end for it (aka template or some such)...
If you provide the template, I'll create the program on the pretnece that it is for your personal use only and it will not be re-distributed without my expressed prior permission!
This is how I usually handle all of my 'non-paid' projects...
~Equinox