sometimes, sweet opportunities are not advertised. talk to docs in fields you're interested in, and tell them your intentions. youre early in the game, and theyre very accomodating in general, especially MS1's.
i was in the same boat as you. i got a job writing articles for a board-review online resource for residents. i worked on it a few hours each evening. during the day, i'd shadow docs. afternoon, i might do some work with them. or i'd shadow a different field. i'd party at night.
btw, if you're into surgery, if you keep shadowing the same surgeon, he'll eventually walk you through parts of the surgery, and let you do some stuff. and by stuff, i mean more than fat retraction. not sure if it's true nation-wide, but it's been true in my experience
overall very enjoyable.