If you like to have fresh air blowing around your home or office (probably not at this time of year) but are concerned about the security risks of leaving a window open then Window Cop could be the answer.

Window Cop is an adjustable window screen which lets air in but keeps out bugs and scares off potential intruders. If anybody tries to tamper with or remove the Window Cop it will let off an ear-piercing alarm. The Window Cop is easy to install and no tools are required, it currently only works with double hung windows but a version for sliding windows is in development.

Website: Window Cop found via Home Security News via Untangled Life.