If you are looking for an alternate file manager for Linux, Marlin can be a good one. Marlin File Browser is a quite elegant and sleek yet fast GTK3 based file manager with some unique and powerful features. Marlin File Browser has integration with Dropbox and Ubuntu One [Needed additional plug-in], compress and comparison, color labels for folders and as well as files and more. Marlin is available for elementary OS daily PPA and thus it can be installed in Ubuntu.
To install Marlin in Ubuntu 11.10, add the
ppa:marlin-devs/marlin-daily PPA to the application source. Then you should be able to install Marlin package from Ubuntu Software Centre.
Or try out the following commands.
sudo add-apt-repository ppa:elementary-os/daily
sudo apt-get update
sudo apt-get install marlin marlin-plugin-dropbox marlin-plugin-ubuntuone