I just got a brand new Dell, it now has Windows and Freebsd. This means that i have all major Operating systems(Mac OS X, Freebsd, Ubuntu, and Windows, in the order of loveliness). The biggest problem in using a lot of machines is that most cookies, browser history, passwords and usernames were just not available. So you end up either remembering the sites, their usernames, passwords etc, and you end up not using the machines effectively.
Enter Weave, for Firefox, the best browser on the web. Weave is a very simple firefox plugin, It keeps all firefox data (Tabs, Cookies, Forms, passwords, browsing history, favorites) centrally on the mozilla’s servers (obviously encrypted), and periodically syncs all the browsers. Now it does not matter what machine or Operating system I am running. Way to go Firefox!!!