Mobile Accounts (webtops)

This is more a "techy" based question, but I'm wondering if anybody is using mobile accounts for their users, and if so what kind? We are a Mac based district and use mobile accounts built into Apple's server so it is not an issue. However, I have just read about some online mobile accounts called "WebTops". Basically, you can create your own desktop up on the web, and all your applications and files will follow you to any machine anywhere on the internet, hence thee "ultimate" mobile account. Although, from everything I have read they are very very slow and I'm sure security is an issue as well.

Check them out here...

http://eyeos.org/en/

http://www.glidedigital.com/