I've been playing around with the latest Visual Studio web development tools. I've made a loan calculator that has options to include additional fees both up front and periodically. You can use it to figure out what the equivalent interest rate is if there were no fees, but you paid the same amount. I also added a compound interest calculator, because, well, it was easy to do. I'll eventually get charts on there, but for now it just calculates the total.
It's at http://www.actualinterestrate.com/
