At home on my computers, I don't have Microsoft Office (Word and Excel). I use Google Docs for word processing and spreadsheets, almost exclusively. (When I need something very high powered and fancy, I use OpenOffice, but that is very rare--about once every three or four months.) Even at work, nearly all my document processing is done with Google Docs.
Google Docs is probably the best example of cloud computing, and is one you can get into right now, for no cost or downloads. If you have an account at Google, then you already have Google Docs, and can use it right away. Just go to http://docs.google.com and start making your computing life simpler!
With Google Docs, you can create your documents online, and share them with others. You can allow others to view your documents, or you can allow specified individuals to "collaborate" with you, where they can also edit your documents. If you have collaborators, you can even edit the same document at the same time!
There is also a document sharing mode called "publishing" which can put any document on the Internet as a public web page.
If you don't have an account, go there and sign up for one. You can use any email address you have as your user name. For example, if your email address is email@example.com, then sign up with that address. Then you can use the programs.
I recommend you also get a Gmail address to go along with that. Even if you don't want to use Gmail, it will allow you to maintain a list of contacts which will make document sharing much easier. Or if you still don't want to use Gmail, you can access your contacts list with a non-Gmail google account at contacts.google.com.
When you are in, click on the help link for information about creating and sharing documents.
The feedback page on this web site was created as a "form" in Google Docs. When a visitor fills it out and submits it, the feedback is saved into a spreadsheet in my Google Docs account. When that happens, I get an email telling me somebody has left feedback, so I know to go look at the spreadsheet.
You can also use Google Docs to create a "presentation" like with Microsoft Powerpoint. You can see an example here.
Here you can see a good discussion of Google Docs and how it works. And here you can see a short video on how it simplifes things.
With Google Docs, you can publish a document to a web page with only 3 or 4 mouse clicks.
At http://www.guardian.co.uk/data-store the British newspaper is making much data available to the public by using Google Spreadsheets.
Here is a sample, which contains county by county results from the 2008 U.S. presidential election:
If you open that spreadsheet and scroll to the bottom, you will see a link to "edit this document". Click that, and you will be able to download the data in a variety of formats from the "File" menu that appears above the spreadsheet. If you are logged in to your Google account, you will be able to immediately save a copy of the spreadsheet to your Google Docs.
It has been reported that the U.S. Department of Justice is running a pilot implementation of Google Apps.