ProximitySwitch

What is it?

ProximitySwitch allows you to put a sign near any lever and, based upon the information on the sign, enable you to activate the switch remotely.

Setup

A standard lever switch...

Smack it to turn it on and off...

With ProxmitySwitch, you can hide the guts...

Make a sign like so:
Line 1: ProximitySwitch
Line 2: Player name to restrict to (can be left blank for all players)
Line 3: Name of material that must be in hand to activate (can be left blank for all materials)
I am using the Material names from: http://jd.bukkit.org/apidocs/org/bukkit/Material.html.
Line 4: Blank

All set up.

Now cover it up.

And all you need to do is right-click near the hidden switch, with the proper material in hand, and the switch is activated.
The maximum distance a player can be from the lever as well as the maximum distance the sign can be from the lever can both be modified in the config.yml.