This is going to sound stupid but you should pick up as many as are useful to your specific needs. If you are super desperate for money, you might end up with a ton of angels. (Just remember the tradeoff that you will be managing a ton of personalities forever.)
On the flipside, if you can find a small handful of angels that not only bring money but who can help you with sales, marketing, or operational, then go for it.
Never forget the time commitment that you have to put in to every single person who gives you a dollar.
I agree. My rule of thumb is that you need to shrink a project down into 3 month deliverables. If you aren't going to deliver something that stands alone and is useful in 3 months, then don't bother as the world will likely change before you finish. I realize that some big projects and products take much longer than 3 months start-to-finish but there should always be 100% useful milestones every 3 months.
It is nearly impossible to stay "the best" for a long time. Apple is going to be great and very profitable for many years to come. But the amazing run they've been on for the past decade will slowly start to fade as entrepreneurs around the world all try to take a piece of their billion dollar business.
Exactly the same in my town. My 13 year old daughter and all of her friends are Instagram users. I'm not sure if they are rebelling against Facebook but they love texting and Instagram. While I like emailing and FB. Generational differences...
Here is my own piece of financial advice that I learned from a wise man 20 years ago: You have to double your income in order to improve your standard of living by 10%. Many people get a raise or a new job and they think they are now rich and can spend like crazy. You can't. Double your income and you'll honestly only see a 10% lifestyle change. Don't forget it. Keep saving. Limit spending. And give a percentage of your income back to charity.
Cool concepts. But TripIt's mobile app isn't as bad as you are saying. I can always quickly and easily get what I need from it. The mobile app is one of the few "pro" upgrades I actually pay for on any app and it is worth it for someone who travels 15+ times per year.
I believe that most developers will gain 1 hour per day of productivity by having at least 2 monitors. Any company that isn't paying for multiple monitors is making extremely foolish management decisions.