I've been thinking about this question lately and since the Dilshan scoop was introduced, it makes this idea less crazy: having a long stop on the boundary right behind the wicketkeeper.
Especially in the last five overs, tailenders can nick balls either side of the wicketkeeper and pick up valuable runs.
I'm not sure where you would take the fielder from. Maybe deep midwicket, and ask your bowler to bowl off side or yorker length?
What do you think?