VMware player is a great free tool for creating virtual machines and desktops. For instance, you can create a new virtual computer to install and test the new Windows 8 Consumer Preview.
Power Search was a real useful feature and there is now good reason why Apple decided to ditch/hide in iTunes version 11. But luckily you can bring it back quite easily. Check it out.
If any file can not be deleted, then you can use the program LockHunter, which removes the active connections of other applications to that file, which allow you to change or delete file.
If you use a lot of different usernames and passwords it is difficult to remember all of them. KeePass is an interesting solution where all your passwords are kept in one safe place and protected with one password.
FTP is a file transfer protocol for exchanging and manipulating files over computer network. We will use FileZilla software to build our own FTP server that actually works.
If you are a heavy twitter use, possibly with more then one account, than I suggest you to give Tweetdeck a try. You can arrange, schedule, monitor and manage your tweets with ease.
RawTherapee is a free open source application for opening and editing RAW image files. It works on all major operating systems such as Windows, Linux and Mac OS X.