Agreeing with others - there is no black-and-white when it comes to companies. There are pockets of exciting and innovative teams in even the biggest, slowest-moving companies, and there are small companies that will suck the life out of you.
Take Washington Post, for instance. Big, lumbering, dead-trees news org, right? Check out WaPo Labs sometime - they play around with projects that you might not expect from BigCo. I worked in a division of a big online company for a time, and we had a great culture as a division, and also within the smaller team I was on, a real drive to move the needle in new ways for the business. I've also worked in a 4-person company that couldn't get itself organized enough to get meaningful work done. Long story short, culture of the team and company are probably going to be more important than size at the end of the day. Oh, and industry will probably make a difference as well. If you can't get excited about MS Excel, don't work for the MS Office team - maybe try the XBox team, or a different field entirely.
Re: college, bdunbar makes a good point - there's a ton of hype around skipping it or dropping out and jumping straight into starting your own company, but personally I'm still on the fence about that. If you can stick it out to upperclass years in school, you'll have a lot more latitude to take courses you want, which will by definition make school more interesting for you. Call me biased, but I think having a degree on my resume has served me better than not having one would have.