Installing Flock, “the social web browser”, is quite easy in Ubuntu.
First, download the latest Flock .deb package from GetDeb. Once the package is downloaded, double-click to start installation. After the installation is complete you can open Flock by going to the Applications menu -> Internet -> Flock.
If you have any problems installing the Flash plugin in Flock, here’s an easy way to get it to work (supposing you have it installed in Firefox):
Open Terminal (Applications -> Accessories -> Terminal) and run the following command.
sudo nautilus /usr/lib/firefox/plugins/
You will be asked for your password. After you enter it, Nautilus would open the above directory. Inside the directory there will be a file called “flashplugin-alternative.so”. Copy it and close the window. Then run the following command in Terminal.
Once again Nautilus would open the directory mentioned. Paste the file inside the directory and close the window. Then close Terminal and restart Flock.
Modified from: Help for Linux