When it comes to content, the easiest thing for us to do as Federal agencies is publish a PDF. Some of the most informative documents on agency web sites are things like their strategic plans, their reports to Congress, their budget justifications, etc. Too often, in the interest of speed of publication, the pages with this type of information become document farms for 100+ page PDFs. These are information-rich documents with high potential for interactivity, but for whatever reason we lock that content away in a static form.
This has to stop. If newspapers and magazines can make this type of content interactive on the fly, so can the Federal government. 44 USC 3506 makes it clear that access to underlying data in agency reports is required; this is reaffirmed in the President's Open Government Directive.