Just a quick mention of a software that helped me with a small problem: I had bought an alarm clock which wakes you up with your favorite song as mp3 file on an USB key or SD card. Unfortunately it turned out that the volume setting in alarm mode cannot be changed, and getting woken up by music blaring loudly wasn't especially nice. I thought about buying a different alarm clock, but then I had an idea: The volume of the music must be somewhere encoded on the mp3 file. If only there was a way to easily change the volume of a bunch of mp3 files!

Turns out, there is! MP3Gain lets you change the volume of a bunch of mp3 files to the same loudness. While mostly meant to normalize the songs on your mp3 player to have the same volume, it also worked beautifully for my purpose. 80 decibels is enough to wake me up without giving me a heart attack.