Two old iPods (30 & 80 gig) batteries were dead. Otherwise they were in pristine condition. Apple repairs were too costly and time consuming for my taste.
I followed the iFixit instructions and watched videos. As others will testify, opening these little beauties is THE HARDEST part of the job. My 30 gig finally opened without any damage and the battery replacement was a snap. However my poor 80 gig suffered significant cosmetic damage as well as the LCD display was damaged just from trying to open the darn thing. Yet it now works great as long as I have it plugged into a vehicle and don't need the iPod display screen.
If you are prissy about your iPods and don't want to risk damage spend the money and time and take to Apple. In my case these iPods were useless without new batteries so it was worth the risk. Opening them is the only hard part. Be especially careful around the screen it is the easiest area to start the process but it is also where the most damage can occur. For $40 they were both fixed in three days time (from battery order to repaired).