Then today I realized that I could use HTML in Google Gadgets. So I can just
- Put all HTML in an XML file and upload the file to SVN.
- Insert a <wiki:gadget/> with URL to the wiki page.
I've immediately changed CopyingTextFromSafari, and also added a Donate button to the front page after figuring this out.
One slight note is that the HTML you use will live inside an iframe.