There are a number of ways you can do this. For starters you can add posts on the Twitter site itself using the post box at the top of your screen when you have signed in.
You can also post to Twitter by IM and even by SMS although if you are posting from South Africa on your mobile phone you will be posting to a number in the UK so watch out for the SMS charges! Of course yet another way you can Twitter is through a desktop application you can install on your computer. I have installed Twitterrific which is a desktop client for the Mac and which shows me updates as and when new posts come in and which also enables me to post new items to Twitter.
As Scott Jangro points out in his post titled “Why I Hate Twitter“, because Twitter is being used for big announcements and day to day small stuff, it can become an addictive service where someone will post something and you will respond and eventually get caught up in a virtual IM (instant message) session over Twitter. That being said, Twitter is being adopted by politicians in the US Presidential election process (John Edwards has a Twitter account), by A-list bloggers to talk about what they are up to as well as the rest of us.
If you would like to track my Twitter feed you can check out the sidebar widget I added to Wired Gecko. It is a really handy way to see what someone is up to if you don’t have a Twitter account. I am unsure how valuable the service will be over time. I suppose one big question is whether Twitter is just a fad or a trend that is due to continue. A similar feature exists on Facebook at the moment where you can add status messages. That feature’s reach is limited to Facebook itself but there it is. Do you use Twitter? What are your experiences and thoughts?