I’m guessing this is what the Office team at Microsoft had in mind when they opened up the Ribbon for extensibility in Office 2007. We have something similar with Office Live where you can choose to Save direct from within Office apps to an OfficeLive Workspace but we don’t have the embedded nature of SlideShare that makes sharing PowerPoint’s so simple. However, having just re-acquainted myself with OLW I’ll be using it a LOT more in 2009 as it’s brilliant for sharing and commenting on slides over the web.

If you want to install the SlideShare add in, here'

Install Instructions

1. You need PowerPoint 2007 for Windows. Earlier versions of PowerPoint, and PowerPoint for Mac, are not supported (yet). Supported versions of Windows are Windows XP with Service Pack 2 or greater and Windows Vista.
2. IMPORTANT: Check in "Control Panel>Add or Remove Programs" to make sure you have the latest version of the .Net framework (Microsoft .NET Framework 3.5 SP1). This is a mandatory pre-requisite for the SlideShare Ribbon for PowerPoint.
3. If you don't have .NET Framework 3.5 SP1, you need to install it from here before installing the SlideShare Ribbon.
4. Install the SlideShare Ribbon for PowerPoint from here after making sure that you have Microsoft .NET Framework 3.5 SP1 installed on your machine