From Andrys Basten’s A Kindle World Blog comes a useful tip:
In the blog article with many general tips on using the Kindle Touch and Kindle Fire, I went into detail on dealing with web pages or with PDFs in which you can see the full page but which are usually unreadable in that format or screen width on a smaller screen than we use with considerably larger computer screens.I've found that many news-site reviewers still don't know about a valuable Android feature that is crucial to enjoyment of web pages on small devices (this applies to Android smartphones also), and of course those just using a device like the Kindle Touch or Kindle Fire won't tend to know about them either. So I'll focus on just this topic here, with all the new Kindle owners after the holidays and because those who did read the earlier article will probably find it difficult to remember where they may have read about tiny fonts on web pages and probably skipped the section anyway in an article that included many other tips.