There are a lot of Twitter clients for Linux out there. Some are quite good; and many are not upto the standard.
Hotot is a Twitter client for Linux that I have come across recently. Having used it for around a week, it is the second best Twitter client for Linux to me. The best is still Choqok.
The most striking thing about Hoto is the interface. It has a smartphone type of interface - with really neat transition animation between pages.
Hotot supports not only Twitter, but also Identi.ca. Setting it up is very simple - for Twitter, click on a button, authorize from a browser and enter the PIN and for Identi.ca you just need to enter the username and password.
Feature-wise, it has almost all the features you would expect from a Twitter client and some more. Hotot supports some extra features like translating Tweets which is in another language through extensions.
One glaring drawback of Hotot is however the way it handles multiple accounts. It can handle multiple accounts all right, but it does not handle them simultaneously. You have to log out from another account to use the other one. If not for this, it would be one of the best Twitter clients available.
If you use only one main account, Hotot is a very good option. If you actively use more than one, you should probably look at another client.
Here is how to install it in Ubuntu:
sudo add-apt-repository ppa:hotot-team
sudo apt-get update
sudo apt-get install hotot