Has anyone tried the upgraded batteries for the 3G iPod? Here is a link: http://www.pdasmart.com/ipodpartscenter.htm They claim to get up to 35% more battery life than the 8 hour 3G iPod batteries (that's almost 11 hours). I bought my wife a refurb 20GB 3G iPod recently and bought myself a 40GB 3G iPod this week (had been delaying buying myself one because of the 8 hour battery life compared to the 10 hour battery life on my 20GB 2G iPod....but I went over 20GB awhile back when I put the King James Bible on my iPod ). I thought the battery life on the 2G iPods was great....but 8 hours, while not a huge difference than 10 hours, is very noticeable to someone like me who listens to their iPod ALL of the time. Just curious if the battery life is that much more noticeable....if so I'd like to shell out the $55 to get this. Though would this void my warranty? Thanks!