Similar to ambidextrous, except you show particularly good dexterity by using your feet and/or toes too.
Having good control over the use of all 4 of your hands and feet.
Like picking things up with them..
Not unlike a monkey.
"I'm left handed AND right handed.."
"Really? I'm left and right footed.. I'm quasidextrous."
"Mate! I just used my toes to play the playstation!"
"Dude, that makes you, like, totally quasidextrous."