If you place a block behind you, a redstone source on the second block in-front of you, and then the piston on the inside block. The piston will active it and allow you to be inside of it. The attached picture shows what happens.
MC-6360
In Piston
Resolved
Duplicate
0
ReduxMC
(Unassigned)
Unconfirmed
block, piston, redstone
Minecraft 1.4.6, Minecraft 1.4.7, Snapshot 13w01a, Snapshot 13w01b
Retrieved
Duplicate of MC-3004 and MC-108