Bukkit

Linking a turnstile chest to a redstone signal instead of a turnstile gate.

e.g. A redstone torch that is off but upon placing the correct item in the chest the torch (or other redstone object) turns on. a similar redstone signal to that of a button would be emitted (non permanent)

this would allow you to open more intricate gate systems with pistons, hidden dungeons etc... that require a cost from the turnstile