Google Apps offers the suite of Google’s applications for the business. You can move your mail and files to the convenience of the cloud. Add the power of Google search, getting things done is never easier. I like have my Google personal mail so much that I even move my personal domain mail to Google Apps.
Google Apps used to have this really attractive offer for up to 5 users, you have all of the above for free. This is now changed to USD$5/ user/ month.