Another member - Sunriselad - beat you to it and created a utility to do most of this. It's called Mine Minder, and includes the block values, pool hash rate, and current difficulty. It also displays a current bitcoin value, but I do not
Thanks for the info Sir Alan, but the program you are referring to requires windows. Although I do work on a windows workstation daily, it's not on 24/7 but I do have several linux VPS's running 24/7, which is why I wanted to use php/mysql. Also, I'm not sure if the windows app just shows live info, or actually collects and stores the data for later use. My intention is to store the info in my own database so I can use it to do long term ROI calculations. Something that tells me over a longer period of time what my daily revenue is, minus hardware costs etc etc. Kinda like the online calculators you can find everywhere, but then specific to my hardware, slush's pool, and not as a a forecast, but looking back.
Maybe a forecast would be a nice to have so that I can predict how much longer my hardware remains in the money, but I'll have to see how much time I'm willing to spend on this!

Well, if you don't mind writing ugly code then think this would be doable in a macro for calc (apache openoffice) to snap your html stats page every so often and extract data from new rounds since last query -- could also grab your account page to check on worker health. Another macro to run the ROI stuff, another macro for any statistical analysis you might want to do, and a macro to merge current data into your mysql db if you decide not to keep it in calc. This approach would also be more or less OS independent.