Excellent thread - thanks!!
I hacked together a quick Google Docs spreadsheet to play with the numbers for my own uses, and I'm in the process of creating a small website with an SSS-style calculator on it.
I'll keep you posted when it's up.
Did you see this,or is it not SSS-like enough for your tastes?
http://xzist.org/amazing-bitcoin-retirement-fund-calculator/You're welcome to re-use the source.
No, I had not seen that one! That's what I get for skimming though page 4. Nice work, I like playing with the delayed gains option.
Anyway, the one I was working on is done now too:
http://bitcoinsavingsplan.com/Comments/criticisms/error checking welcomed

Beautiful work. Thanks for sharing it.
If you are interested in adding an additional feature, I would suggest that the "doubling" and rake be more fully variable. For example I will likely be using a more continuous withdrawal plan such that I sell 1% of BTC at each 10% increase in ATH. I'd ideally like to play with these variables as well. I am able to do that on at least one of the other calculators posted in this thread.