It's used as an adjective to describe something being awesome, legendary, or ridiculously awe-inspiring. It is usually preceded with an event that is unforgettable.
"Yo that movie 'Dark Knight' was ShoMoney!"
"Did you hear about that billionaire?! It must be shomoney to have that much money! "
"'How I met you mother' is soo shomoney."
"Man! you were so shomoney last night at that party!"