hopefully supported: iOS 2.2 through 9.0
Cydget is a flexible and powerful replacement system for WinterBoard Lock Widgets, allowing users to have multiple lockscreen displays active and to cycle between them.
Users configure Cydget using a reorderable list, similar to configuring WinterBoard: go to the "Settings" app and choose "Cydget" to activate, deactivate, and reorder cydgets.
...but, unlike WinterBoard Themes, if you have multiple cydgets selected, they do not "stack" on top of each other: instead, you can cycle between them by pressing the home/menu button at the lockscreen.
The Apple original lockscreen can be added to your rotation and is called "AwayView". If you wish to have access to its features, including "double-tap home button for iPod controls", you should leave this cydget in the rotation so you can switch to it.
Cydget is built on Apple's "SpringBoard plugin" mechanism, so it does not conflict with other Apple-provided lockscreens, including VoiceRecorder and Nike+. However, some jailbreak lockscreen extensions are not compatible with Cydget, which may cause humorously overlapping displays if you have multiple lockscreen extensions active at the same time.
Therefore, I encourage developers to design lockscreen extensions in a manner compatible with SpringBoard plugins, in order to minimize community code conflicts.
An example cydget is included to demonstrate the technology: show a random picture from your camera roll.
Some of Cydget's core benefits (over WinterBoard Widgets):