Current versions of MSIE and Firefox are a must. Ideally your flakes should also work with Opera and Safari, as well as with older versions of MSIE and Firefox.
You are free to give the flake the design you prefer, although it is a good idea to check out a couple of the existing flakes to get a feel for our Look & Feel (no pun intended). If you belong to the many developers for whom design/UI work is simply a pain in the a..., we are more than happy to help you with that to let you focus on what you can do best. Just contact christoph@pageflakes.com if you need assistance.
Just call _module.refresh() .
By default, all links should open in a new browser window. Ideally, add an option to Edit Area where the user can choose between "Open links in new browser window" and "Open links in this browser window".
Flakes having an .html extension are cached, flakes ending with .php are not. To avoid caching, simply rename your flake to *.php. It doesn't have to be a PHP file, of course. It's only a trick to fool us that it's a dynamic file and shouldn't be cached. :-) When everything is final, rename *.php to *.html again.
Your favorite blog feed is missing in our directory? Or you've developed a flake and want to add it to the site? We look forward to your contributions!