After seeing it in the AppStore for weeks I finally decided to download to my iPhone and give it a try. 

There's Web, Mac, iPhone and Windows clients available and they all sync data back and forth.  So far the sync'ing has been seemless and without problems.  On the iPhone Evernote will let you take text, voice or photo notes which is a great combination. The Mac and Windows versions will allow you to highlight any text and have it added as a note to Evernote.  You organise your data by placing entries into "notebooks" and can choose for notebooks to be local only, sync'd to the server or published publicly with an RSS feed.

This is great, my blog can now automatically download entries I put into my public notebook (via RSS) and include them into my web site.  Sweet!

I've actually abandoned the builtin iPhone Notes application (which is ugly and doesn't sync with anything, even Mail.app's note feature ... <arrrgg>) in favour of Evernote.  So far so good, I'm impressed!