Converticon is a simple icon utility. It can import ICO, PNG, GIF, and JPEG formats and export to high-quality PNG or ICO files. There is no software to download and it's 100% free.

Format Factory is a great freeware program.
It can convert many kinds of videos, audio, data/music CD/DVDs, Pictures, and even videos compatible with mobile devices.

It can convert videos into audio.

New versions have more formats- so many, I can't add them all as tags!