Microsoft has its OneNote app for iPhone is available as a free download “for a limited time”. Originally a Windows Phone 7 app….See Details.

But the iPhone app will let you manage notes and shopping lists and add pictures taken with the iPhone’s camera, and then sync those with Windows Live SkyDrive so you can access them in either the Windows desktop application or its web-based counterpart. No word on when the “limited” free period will run out (so you’ll probably want to grab it while you can), And there is no word on a worldwide release, currently only available to US users.