The clue is in the question - ipod battery life is terrible, which is why a lot of users who've been suckered by Apple buy a different player the second time around.
I had a 3rd generation 20Gb which was woeful for battery life and I eventually junked it.
Mainly because I'm a sucker for the design and couldn't be bothered moving all my music from iTunes I took a gamble on a 60GB video ipod and find it significantly better. Its never run out on me, and I use it lots, but only charge it occasionally - far more up to the job.