Articles on co-founder equity issues and splits

I've been spending a bit of time researching information about Co-Founder equity scenarios as well as how to find the right Co-Founder. Some links below I found helpful.

The only wrong answer is 50/50: Calculating the co-founder equity split http://www.geekwire.com/2011/wrong-answer-5050-calculating-cofounder-equity-split/

Foundrs Calculator http://foundrs.com/

The Founders Pie Calculator method http://www.andrew.cmu.edu/user/fd0n/35%20Founders%27%20Pie%20Calculator.htm

How much a non-technical co-founder should receive? http://blog.nahurst.com/how-much-equity-a-technical-cofounder-should

High Tech Startup Valuation Estimator (More for fundraising, but good things to think about) http://www.caycon.com/valuation.php