When the Windows Mobile community sees something they like they are generally not shy in duplicating it for themselves. Such has been the case with the Android pattern unlock screen, where the code to unlock your device is not a sequence of numbers, but drawing a specific pattern on a grid.
The developer of Throttle launcher has whipped up a small application he calls Throttle Lock which duplicated that functionality quite faithfully. If you do not however like Android style the application is fully configurable by simply swapping our the .png picture and editing the configuration file. The application also supports multiple languages.
See the video demonstration here for an example of the application in action.
Download the application from here.