It might have seemed impossible, but PowerPoint and Excel are about to become even more pervasive.

A new feature in Microsoft's Office Web Apps will give users the ability to embed their presentations and spreadsheets in blog posts and other web pages, giving people who visit their sites a new type of window into their documents. The feature is part of broader set of incremental improvements that Microsoft is rolling out today for the 3-month-old Web-based versions of the company's widely used productivity programs.

OK, so let's give this thing a whirl. Continue reading for my embedded version of a PowerPoint presentation distributed by the company to explain how PowerPoint embedding works.

Of course, the concept isn't new. Services such as SlideShare allow users to embed presentations, and Google offers the ability to embed spreadsheets in web pages from Google Docs, for example.

However, Microsoft is hoping to stand out from its competitors. The company "worked really hard to make sure that the formatting is preserved," said Evan Lew, an Office Web Access product manager. The company is also in a potential position to popularize the technique -- reporting today that 20 million people have used the Office Web Applications in the first 100 days since launch.

The embedding feature works by creating uploading an Excel or PowerPoint document in Windows Live SkyDrive, which serves as the dashboard and file repository for Office Web Apps, and then retrieving an embed code.

Continuing with the very meta demos, here's an embed of Excel spreadsheet that I created showing revenues and profits in the Microsoft Business Division, the group that makes Office and related products. Below that is the same spreadsheet as embedded from Google Docs.

People with access to the Excel document on SkyDrive can make changes that will then be reflected in the published version.

[Update: Here's an Excel help page that shows how to customize different aspects of the embed code for things such as interactivity by web viewers.]

Other new features in the Office Web Apps include the ability to create charts directly in the Office Web App version of Excel. Microsoft is also bringing over the "fill handle" from the desktop version of Excel, for quickly populating cells with formulas, and it's enhancing the clip-art capabilities in the Web-based version of PowerPoint.

Microsoft also announced that it's expanding the availability of the Office Web Apps to Australia, Austria, Belgium, France, Germany, Russia and Switzerland, from the existing footprint of the U.S., U.K., Canada and Ireland.