I just downloaded Ubuntu 11.04 and as far as I can remember, there was the option of opening multiple terminals in tabs in Ubuntu. I cannot discover this feature in 11.04. Also, as a general query, suppose I open emacs from the terminal, then I wouldn't be able to do anything else on that terminal as long as I have emacs running, so what is a good way to multi-task?
You can also use a terminal multiplexer like
tmux. Byobu is beautifully configured for Ubuntu out of the box. Tmux requires some initial configuration, but is (relatively) easy to customize. Think of it as a command-line program that can run multiple shells organised like tabs.
I prefer to use a terminal multiplexer over gnome-terminal tabs because I can detach and attach from anywhere. Examples:
Login to work via ssh, start a multiplexer with a few tabs. Open a file with emacs, start a huge download, etc. Detach the multiplexer, logout of ssh, go to work. Reattach your session and resume work right where you left it: emacs stayed open, your download continued while you drove to work.
Start writing your research paper (in LaTeX of course ;) on your desktop. Realise it's far too nice a day to be sitting indoors. Reattach the multiplexer session on your lappy outside and continue working.
There a Terminal Quicklist that has the option to open new tab.
Although it's not a new tab you can use the middle mouse on the launcher to open a new terminal.
I would also recommend you look into Tmux as this is a great tool for working in a single terminal screen. For example it will keep your session running after you logout from remote servers.