And recently I came across one of Paul Graham's essays that resonates with my thinking. Quoting pg (http://paulgraham.com/hs.html): "Now I know a number of people who do great work, and it's the same with all of them. They have little discipline. They're all terrible procrastinators and find it almost impossible to make themselves do anything they're not interested in. One still hasn't sent out his half of the thank-you notes from his wedding, four years ago. Another has 26,000 emails in her inbox.
I'm not saying you can get away with zero self-discipline. You probably need about the amount you need to go running. I'm often reluctant to go running, but once I do, I enjoy it. And if I don't run for several days, I feel ill. It's the same with people who do great things. They know they'll feel bad if they don't work, and they have enough discipline to get themselves to their desks to start working. But once they get started, interest takes over, and discipline is no longer necessary.
Do you think Shakespeare was gritting his teeth and diligently trying to write Great Literature? Of course not. He was having fun. That's why he's so good."
IMHO I think you should struggle some more with your discipline problem, and then join an institution such as a start-up, HackerSchool, etc. Internships and programs are great because of the experience you'll get, knowledge and so on, but your lack of discipline when nobody's watching you will still probably be there afterwards. But that's just my opinion!
You sound like you're thinking only short term, and only in terms of keeping yourself busy. That's not how motivation works, unfortunately.
With that kind of approach you never see how your tasks fit into the bigger picture, so everything that comes along is more attractive because it's new. Discipline demands a plan.
Choose a goal that will take you 5 years to complete. Something concrete. Something like "build my own app" or "be an early employee at a hot start-up" or something else that takes multiple steps, and something you feel extremely excited about achieving.
Then outline those steps and get into the first one now. Then when a new opportunity comes along you can evaluate it by saying "is that a better 5 year goal?" If it isn't, "does that get me closer to my 5 year goal?" If not, ignore it and keep on keepin' on.
Voila: discipline through motivated planning.
Think about it. When someone doesn't have the discipline to do something, they think they should probably do it, but don't fully understand what they'd gain by doing it, and what they'd sacrifice by not doing it.
At the very least, understanding why you should do something will provide you with more motivation to do it. I just feel like (in general, not you specifically) if you truly understand why you should do something, it isn't hard to motivate yourself to do it.
So, I think you should sit down and think about what you want to do with your life. Consider all the options, narrow them down, educate yourself on things you're interested in but aren't familiar with, try things out. Once you understand why you don't want to do the things you don't want to do, and you understand why you do want to do the things you do want to do, I think you'll find the motivation to do them.