The K3's WebKit browser is a very useful complement to Kindle's core reading functionality. While not as nimble or functional as many other mobile browsers, it's great for reading a broad range of web content. One feature that makes it particularly pleasant is 'Article Mode', which strips out complex layout and styling and lets you focus on the main content of an article.
To take Article Mode to the next level, I'd like to see a 'Save To Kindle' menu option when viewing in Article mode. This would save the contents as an HTML file to Kindle's 'documents' folder for off line reading. This would enable the ability to resize text, annotate, sharing to Twitter/FB, and use Text To Speech, while retaining the article's hyperlinks. The article could also be later copied to a computer and imported to a word processing document for re-use.
Kindle can read simple HTML files directly without conversion, if the file is given a '.txt' extension. The HTML code represented by the contents viewed in article mode qualifies as 'simple'. At most, href values that jump to other locations within the same web page (many articles have a sort of TOC of links to sub topics) would need to be sanitized so that they jump to the location in the current item instead of launching the web browser.
This would be a low-cost, high-return enhancement that many Kindle users would come to appreciate.