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.
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.
Pixlr is a free and probably the best web based image editor. I will show you how to open and and resize an image, I'm sure you will be impressed how well the web app actually works.
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.
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.
If you want to put your video files online using HTML5 then it's recommended to have three different formats for a full browser support. Those formats are mp4, ogv and webm.
