Maybe under your friend list you can have a message stating that you have friends awaiting approval and how many.
Just like you get a message for how many friends you have pending.
If this feature is already invented then disregard my message, but it be good to know when someone adds you.
VOTED: Maybe, But Probably Yes
[reason for a vote of "maybe", is mailbox could get flooded and a simple message note on profile page of people awaiting approval will void message space.]