My brother, an ESTP, is very much like that. He's always doing something or talking to someone. And yes, like you, he does get a little down and very bored when there's no one around to talk to or do things with. He's always out somewhere, and now that he has his own car, I don't think he's ever often at home.
He also isn't fond of sports, likes to be very clean, can't stand his work space full of distracting irrelevant objects, and likes to cook (okay...he LOVES to cook...he loves Food Network and I think half the fun for him is inventing new ways to combine foods so they taste good).
He's never been one who was good at taking tests, but he enjoys the process of gathering information and understanding it...especially when he's allowed to observe something happening and then play with it to see what will happen. Probably why he's working with stem cell research.
He's very persuasive, but he would not necessarily admit to being so. Unlike me, he can walk into a room and totally work the room to his advantage so smoothly it usually makes me feel like I'm tripping over myself.
So, yeah, there's some evidence of another ESTP. Similar to you, but different in plenty of ways.
By the way, have you considered taking up cooking? Seems like it'd be right up your alley.
Making tastey foods you get to devour shortly after making them seems rewarding enough, yes?