I have made a risk of ruin calculator that I am happy to offer out to other affiliates. You can check it out to see how it works here...
http://www.thepokerbank.com/ror.php
You can use a risk of ruin calculator for a number of things as well as poker, and can be used in almost any gambling situation. So it would be useful on any gambling site and not just poker. The calculator should help to make sites a little stickier, as players can come back to use the ROR calculator for any gambling ventures now and in the future.
All I am asking is for a text link in return for the calculator. A text link on the same page would be preferable to keep things simple, but I am open to suggestions for having a text link on a different page if you wish. I'm not after the world in exchange for this calculator, just a standard link back from somewhere decent to say thankyou.
I will help you install it if you like (it's just copy and pasting some code really), and I will also help you customize it to suit your site/page if needs be. Also, I'm not going to be using this calculator on my site quite yet, so I guess you've got an opportunity to get your hands on it and start getting links and ranking well for it.
Just shoot me a PM or add me on MSN (preferred - look at the top right of this post for my addy) and I'll sort you out with the calculator.