How To Reclaim Space on an iDevice

Okay, if your like me and have a lot of music (I'm talking 3-4,ooo+) you may be running our of space on an iPhone, iPod Touch, iPad, ect. (even though I had the 32GB model). I found a check box within iTunes that can turn 25 GB into 13GB easily. Plug in your iDevice and open iTunes, navigate to where you can see your iDevice and under the summary tab check the box that says "Convert Higher Bit rate songs to 128 kbps AAC". What does this do exactly? Well, I get most of my music from HQ CD-rips (my own) as well as iTunes and official mixtapes, which are some of the highest quality music files, and while this is nice on my computer, it takes up a lot of space on my phone. To most listeners, you won't hear a difference, the only time I do is when I plug my iPhone into my BeatBox by Dre and really listen for it. All in all this is a very helpful find so far.