If you want to slightly raise the maximum volume of your iPod, you should give this program a try.
All you have to do is install it and then connect your iPod to your computer. Then, you can unblock or reinstate the maximum volume restrictions.
You should, of course, use goPod responsibly. But it will come in handy if you've noticed that your iPod's volume leaves something to be desired when compared with other players.
If you regret having lifted the restriction, just follow the same steps and it will be reinstated. Remember: it's not worth losing your hearing just to turn the volume up a few more decibels.