Apple's iTunes News has posted up a helpful tip on how to use the new automatic 128 kpps downsampling function in iTunes to squeeze double the music (if lower quality) onto your iPhone, iPod touch, or iPad.
Audiophiles will no doubt rather scratch their ears out than listen to anything that highly compressed, but if your ears are more greedy than golden, the 128 kbps downsampling might just be for you.
You can find it when you plug your iPhone, iPod touch, or iPad into iTunes over USB, on the general screen that comes up. (See screenshot, above). Here are the extra-geeky details: