In Ubuntu, if you want to view your current keyboard layout, you need to go into Keyboard Preferences and open up a rather bulky keyboard to refer to. None of the accessibility-oriented on-screen keyboards that I found through apt or the repository support alternate input layouts or alternate input languages by default. Please consider finding some on-screen keyboard that displays the current input layout to include in Ubuntu's default config. This is a basic international functionality need which could easily be met in Ubuntu's default install package.
Update: I realize that the layout switcher, when you right-click on it, has an option for "Show current layout". Still, this functionality should have more visibility; as far as I know, right-clicking the layout switcher is the only way to find that window.
I tried to type in Tamil. I installed the required font and keyboards and I have the option of switching between English and Tamil. No issues. I want to use Tamil in Office I do not know which button to press for which character in Tamil. Ubuntu / Office can have an option to display the onscreen key board, so that it easy to learn typing other than english. I use Ubuntu 10.04. Kindly ignore this advice if it is implemented in Ubuntu 12.04