I have accepted a friend and I still can't find them... Says location unavailable... But he can find me!

Here are some things to check from http://support.apple.com/kb/TS4008:

"No location available" label for friends

This can occur if:

• the date on the device being located is incorrect. This can be changed in Settings > General > Date & Time.
• the device being located:
  • is turned off
  • is not connected to a data network (cellular or Wi-Fi)
  • has Hide From Followers turned on in the Find My Friends app
  • has Location Services turned off altogether in Settings > Location Services or has Location Services turned off specifically for Find My Friends in Settings > Location Services > Find Friends
• your friend is currently not signed in to the Find My Friends app on the device being located.
• the device being located is currently in a country where Apple does not offer this feature. This feature may not be available in all countries due to technical limitations or local law.

Having the exact same problem; have 4 friends added, we're all at the same city, all of them can find me, I can find NONE!

I've been having the same problem with my son's iPhone. His phone was water damaged and subsequently replaced at an Apple Store. After restoring the data Find My Friends worked for him but not for me: he could see my location but on my devices his was "not available".

I think this fixed it: on his iPhone I logged in to the Find My Phone app and then went to Me → Account → Active Device. It turned out his old device was selected on the list of his devices. (He had renamed his new iPhone after restoring the data so it was easy to notice.) I deleted the old iPhone from the list (swipe, "delete") and selected the new iPhone and instantly his located showed up on my iPhone.

I hope something like this works for you. Check that the correct device is selected in your Find My Friends account.