Today is a real milestone for people who use Windows Live. Starting today, a select group of SkyDrive customers will be invited to try out a technical preview of the Office Web Apps which are online companions to Excel, Word and PowerPoint, available for free via Windows Live SkyDrive. Over time, as the final version is released, the Office Web Apps will become available to all 500 million+ users of Hotmail, Messenger and other Windows Live services.

While the tech preview doesn’t have all the cool features that will be available in the final offering, it does show off the exciting potential of extending your Office experience to the Web. You can easily access and work with your Office documents from virtually anywhere with an Internet connection.

When those of you participating in the Tech Preview upload or create a new document, you’ll be able to view them much like you do today using the familiar Office toolbars and user interface. The Office Web Apps provide a high-quality experience in terms of both features and fidelity. . And it will be very easy to share your documents in password-protected folders and give permission to whoever you want to have access – just like with any other SkyDrive files.

Personally, I’m excited that, in the final release of the Office Web Apps, I’ll be able to access Office documents from virtually any PC and then be able to share them, show them, edit them, and collaborate on them with people around the globe. I do a lot of presentations so it will be particularly helpful for giving presentations right from Internet Explorer (or Firefox or Safari). Because I’m kind of an Excel geek, I’ll be able to share my spreadsheets in all their glory – with conditional formatting, charts, and more. In the final release, I will also be able to share notes from OneNote in real-time with others.

Over the coming months here are some of things you can expect to be able to do in later versions of the Office Web Apps:

Why are we making Office Web Apps available as part of Windows Live?

We all use a lot of different services online – e-mail, social networks, photo sites, video sites, and so on. In many cases, we use more than one service for very similar purposes, using Facebook, MySpace , StudiVZ, Mixi or many others for social networking; Hotmail, Yahoo!, or Gmail for e-mail; Flickr, SkyDrive, FotoLog, or Photobucket for sharing photos.

That said, there are certain things we really just want one of. I really just want one place for storing contact info, one personal calendar I can share with my family, one primary mail service that also allows me to check all of my e-mail accounts, one place to get updates from all of my social networks, and one place to store, share, and manage my massive and ever-growing collection of photos, documents, music, and videos.

I can get all of that at Windows Live. And now, with the addition of Office Web Apps, I’ll soon be able to go to Windows Live to create, edit, share, and collaborate on Word documents, PowerPoint presentations, OneNote digital notebooks, and Excel spreadsheets –all online regardless of which PC I’m using and whether that PC has Office on it.

I’m super excited about today’s release and the future of Office Web Apps. Over time, we’ll add the OneNote Web App to this experience as well as expand both the functionality and the number of people who get to try out the services.

Today’s a great start on terrific things to come.

If you weren’t one of the folks that received an invitation today, sign up here and we will let you know when you can try it out too.

Stay tuned.

Brian Hall