Where is "search" on the iPod nano 6th gen?
It looks like this iPod doesn't have this feature: it's not mentioned in the manual (http://manuals.info.apple.com/en_US/iPod_nano_6thgen_User_Guide.pdf) - even in the index.  

However, you can go to all items starting with a certain letter.  From the manual (on page 20):


  If the list you’re browsing has an index, drag your finger down the
  index to show a large letter superimposed over the list. When you
  reach the letter you want, lift your finger.