iPod headphone jack only driving one side - is there an easy way to fix this?
I believe your iPod’s audio jack might be failing. If you really like your iPod and want to “repair it”, you can. Google for iPod 5th gen spare parts and you’ll find tons. 

For exmaple: This one has a iPod 5g 30gb Audio Jack for $35. They also have the “right tools”. I have no experience with either, but I know people who has fixed iPhones and stuff like that by simply buying the pieces.

They claim: 


  Is the audio port / headphone jack of your 5th generation iPod Video only working out of one channel or the other? Are the plastics cracked or broken and your headphones held in place with duct tape? Order this part to replace your connector or open a repair order below and let our qualified technicians repair or replace your connector to get you back in stereo!


And they also offer a service where you can send the iPod and they will do it for you.
Of course, there might be others that do the same.