Browser Feature Detection - Plugins

Feature detection is the best way to ensure a good user experience when browsing the web. Rather than presuming an iPhone can read pdf's (which it can). We should be detecting whether the browser is capable of displaying pdf's natively first, then embedding the pdf (in a new window seems the best option). Non-supported browsers could be shown a download button and message telling the user where to find the relevant plugin.

Here is a great post showing how browser plugin detection can be implemented easily using JavaScript:
http://www.matthewratzloff.com/blog/2007/06/26/detecting-plugins-in-internet-explorer-and-a-few-hints-for-all-the-others/