This is an experimental, mostly proof-of-concept application that adds "widgets" onto your WP7 lockscreen.
Download releases @ http://windowsphonehacker.com/articles/release_lock_widgets_2-07-03-12
The source is a horrendous mess, as this application has to use some bizarre hacks to get around the OS memory and background lifetime restrictions. As such, it's not really recommended to use as a daily application.
Licensed under GPLv3. In (unofficial) laymen's terms, you can use this source for any purpose, so long as your software remains under the same license. You can use the use privately for any purpose, but if publicly released in binary form, your modification of the source must be made publicly available under GPL: http://www.gnu.org/licenses/gpl-faq.html#GPLRequireSourcePostedPublic
This project contains fiinix's DllImport library, which is licensed under proprietary terms listed here: http://forum.xda-developers.com/showthread.php?t=1006331