The extra batteries for the flashlight 'came in handy' [=were useful] when the electricity went off.
He always liked to keep a dictionary 'handy'. [='on hand, nearby']
('Brit') My flat is 'handy for' [=near to] the underground.
(..) As you wish. Richard? Richard, You like your earrings? Oh, you're materializing now. Yeah, pretty handy, huh? So you like your earrings? Yeah, there's a bit of a problem. They're too small. No, they're too big. I can shrink them. Let's see... No, that's not the problem. I just-- (..)2004 TvShow: Charmed Title: I Dream of Phoebe Season: 6 Episode 15