Firefox 4 Beta for mobile phone especially for Android and Maemo is now available to download. It build on the same technology as Firefox 4 desktop but optimized for the mobile experience.
The browser also include Firefox Sync to synchronize data between desktop and mobile.
With Firefox Sync, you can take your browsing history, bookmarks, tabs, passwords and form-fill data with you anywhere so you never have to retype passwords or long URLs again. Your Firefox data is completely encrypted end-to-end between your computers so that only you have access to it.