I have found TweetDeck a decent Twitter client. It can, for example, automatically shorten your URLs. It also pops up a message box at the edge of your screen every time you receive a new tweet, which will, however, get annoying if you are actually trying to do something that requires you to concentrate. In these cases I've found it best to just close TweetDeck and to occasionally check the Twitter home page.
What do I tweet about? 5 to 10 percent of my tweets seem to be messages to other users, i.e. comments to something they have tweeted about. I rarely receive any replies to my comments... 10 to 15 percent of my tweets are retweets. That's just forwarding other people's interesting tweets. 20 to 30 percent seem to be my original thoughts about things like movies and everything else. The majority of my tweets are just links to interesting blogs, web pages and articles that I have found from various sources.
Twitter is a convenient way of getting interesting pieces of information and quickly sharing pretty much anything. You can also use it as your sort of public bookmark list by favoriting the most interesting tweets. :)
(Image by Randa Clay)