in reply to Golf: ROT-n
#23456789_123456789_123456789_12345678 $_=pop;for$x(1..pop){y/a-z/b-za/}print [download]
UPDATE: Looking at other solutions inspired an improvement to 36 strokes.
#23456789_123456789_123456789_123456 $_=pop;eval"y/a-z/b-za/;"x pop;print [download]
tilly++. Not the most efficient approach, but defiantely one I wouldn't have thought of.
"There is no shame in being self-taught, only in not trying to learn in the first place." -- Atrus, Myst: The Book of D'ni.