In a new post today Martin Sikora has points out a Google Chrome extension he's created that lets you view some of the basics of the PHP manual without leaving the browser.
Finally, I released my extension for Google Chrome called PHP Ninja Manual (Ninja - because I like Avinash Kaushik'sblog and he always call people who are very skilled in something as "Ninjas"). I was always lazy to open PHP documentation every time I had to look at some method definition and its parameters so I made this extension which is actually preparsed official PHP manual available instantly in a popup window.
You can see a screenshot of it in action here including the auto-complete searching and the example of the function's summary details. If you try it out and have feedback, go over to the forum for it and leave your comments.