xpy is a small software, securing your Windows 2000/XP/2003 installation and protecting your privacy. In addition to so-called Antispy features, it disables common security threats (RPC/DCOM, LMHash) and increases your Windows performance.
Diff-ext is an extension for filemanagers such as Windows Explorer and Nautilus that allows to launch diff/merge tools on selected files.
Link Creation Extension is a nifty shell extension which enables users to create symlink to directories and hardlink to files. It also provides property sheets and shell columns.