Windows helpfully keeps lists of your recent activity all over the place, so you can easily access recently-used files and programs. Keeping track of these lists can be a pain, especially if you like to keep your programs free of activity footprints.
MRU-Blaster is designed to collect and clean up most recently-used lists kept in Windows. Because these lists can hold quite comprehensive information about what you've been doing and where on the system, cleaning them up can be a good way to protect your privacy if necessary.
MRU-Blaster scans Windows for these lists, then brings them up, at which point you can choose to clean or not by checking or unchecking them. In the settings menu there's a big list of programs you can tell MRU-Blaster to ignore in its scans, to tune the cleaning process to your needs. There are also two plug-ins available to clean Microsoft Internet Explorer's cache and cookies.
MRU-Blaster is good at cleaning what it does, but it's a shame it isn't set up for more programs (Firefox isn't supported, for example). Despite this, it makes a long job much much shorter, as you don't need to open each of your programs manually to delete the most recently used lists.
MRU-Blaster is a limited but useful tool for cleaning up traces of your activity around your system.