Ubuntu 11.04 is in beta and scheduled to be released on April 28th, I have been running the beta version on my old laptop and so far I am please. The OS interface is very clean and app doc on the side is very easy to use and configure. The software is easy to use and finding the apps you need is fast. Just about everything you need can be downloaded within minutes and you can be online in a few hours after install.
One of Ubuntu strengths is it's ability to run fast on older / slower PC's, giving them new life and usefulness. If you need a good internet machine with office capabilities and social networking Ubuntu may be the right choice.