How can I compute mining profitability? It was asked elsewhere, but I'm re-asking the question in a less time sensitive way. Can you please list some of the techniques, charts, spreadsheets, calculators or other tools that help someone to compute mining profitability?
There are several mining profitability calculators available.  In order to obtain useful data from these, you'll need to predict how the price of bitcoins and the mining difficulty factor will change.  Price charts are available at bitcoincharts.com, and difficulty charts are available at bitcoin.sipa.be.  There are also charts of the price to difficulty ratio available at bitcoinx.com.