To slyly take someone else's phone when they aren't looking so you can play with it.
That dude phone jacked me right there under my nose!
When your friend asks to *Borrow* your phone for "real quick" and ends up taking way to long with it whether it be five minutes to an hour.
Dustin: Hey lemme use your phone real quick
Mike: Okay man.
30 mins later.. Can I have my phone back
Dustin *Still In arguement with girlfriend*
Mike: "Great, Ive been Phone Jacked."