The 'tooltip' pop-up descriptions on Flat Fee were a particularly interesting challenge, as they were added to the design once I had nearly finished building all the templates, and so I needed to come up with a solution which would degrade elegantly without changing too much of the existing code. I used JavaScript to pull a hidden span from the links and show it beneath the link title text; this allows the script to degrade elegantly, so the information is still available without JavaScript on.
As the designers wanted to use Helvetica Neue for the headings, which is a non-standard font not every visitor would have installed on their machine, and there are many pages with user-contributed content which wouldn't lend itself to image replacement on the text, I decided to use sIFR text, a JavaScript and Flash solution which replaces web text with Flash text, if Flash is available. This ensures the vast majority of visitors will see the site exactly as the designers intended, while search engines and users without Flash or JavaScript installed can still read the text in an elegantly degrading web standard font.