A simple Twitter Cydget client that allows you to quickly and easily post a status update, view your friends status updates, @replies, and more!
Another neat but needed feature is the ability for Twydget to instantly store your tweets temporarily so that you don't lose an important 70 characters. Speaking of characters, Twydget also includes a LIVE 140 character counter. The state of each tweet is automatically logged (locally) and restored if the device goes back to sleep (which would normally clear anything you've conjured up).
Also, Twydget is ran almost entirely client-side (right from your device), instead of relying on third party web servers that may not always be around and available. Not to mention that they might be storing your username and password. By default, Twydget allows you to configure your username and password on the fly, right from the lockscreen. Your username and password are temporarily stored locally on your device, however, a simple respring or reboot will clear these settings.
You can permanently set the username and password, and even show your lock background image by editing (via SSH/FTP or otherwise) /System/Library/LockCydgets/ Twydget.cydget/settings.js
More information at Twydget.com