As you probably know, Twitter completely ditched basic authentication method on August 31st, 2010. It now supports only OAuth method of authentication which complicates the coding process multiple folds. Scripts which were previously 20 lines long now span several files.
While there are numerous advantage of Oauth like client doesn’t need to know your password, increased security etc, lots of twitter clients which used basic authentication stopped working right away after Aug 31st.
However, there had to be someone to the rescue. This time it’s http://www.supertweet.net/. They act like a proxy between twitter and your app, converting all basic authentication requests to oauth requests. So practically, twitter will be getting oath requests and your app would still be making basic authentication requests. This would help the twitter clients or php scripts to still use the same code and function just like before.
The process is pretty simple and you should get through everything without a hitch.
You just have to change the API url from http://api.twitter.com/ from the application settings or PHP code to http://api.supertweet.net/.
If you still have problems, post it in comments.