Linda Shum and I collaborated on this--she created the design in Fireworks for her employer, but then had to leave town, so asked me to work on it while she was gone.
My job was to get as far as I could in turning the design into a Genesis child theme, preserving the design as exactly as possible, with certain functions. My focus was on the home page design (tabbed slider and many widgets with tricky shaded backgrounds; widgeted footer; secondary menus in header and footer areas).
Linda and I will walk you through her creation of the design, what I did to implement it, the mistakes we made, and how we ended up making it work. (For the record, I spent about 18 hours on it and it wasn't finished yet by then, so this is not a small task.) Those of you with more experience can point out all the things we did wrong, and those with less experience can either decide this is more than you want to take on right now, or take notes and get ready to build your own.
The site in question is SparkPoint from United Way of the Bay Area, live as of June 2011.