http://www.mp3-box.org/audacity-mp3-kbps/
how can i reduce the size of MP3 files?
All this ‘kbps’ stuff kinda confuses me.
The problem is – that the majority of my music files in my itunes library are far to big, they are all MP3′s (as far as i’m aware) but some of them are at 320kbps, and some are lots at 10mb plus in size.
I want to convert ALL my songs into MP3 at probably 128kbps.
how can i do this?
what programmes/software do i need/what is the best way to do it?
is there a way where i can do ALL the songs at one time and just leave my computer to work on them for a few hours?
i’ve been told audacity can be used – but i have no idea how to use it – and as far as i’m aware you can only do 1 song at a time.
any help would be appreciated 
thanks in advance.
Dan.
I dont see ‘create MP3 version’ – only ‘create AAC version’ – which i dont want
:S
and when you set the codec in itunes preferences isn’t that just for when you import audio cd’s ? or does it work for this to?
An easy way of doing it would be to use iTunes. Set your codec in preferences, highlight the tracks you want and right click. Make MP3 version will be there and it will encode them to your specified bitrate 
Nasty ninjas mix EVIL TIPPED SHURIKENS