Rentacoder and eLance are neat ideas, but they have the same problem that the job market as a whole does: you want good code from good hackers, and if you're not technically inclined yourself, you will have a very hard time determining who is a good hacker and who just talks the talk.

If you want a technical startup, you need a technical cofounder. "I'll just outsource the development" will doom you to failure. I know this because I am an employee of a startup that thought that way, and learned the hard way that execution matters; and spending umpty-million dollars in the first year on outsourced projects that you wind up needing to pay umpty-thousand-dollars in the first year of operation to replace -- well, let's just say that, even with venture capitalists involved, burn rate matters, and money you spend stupidly still counts as an expense.

When I have "umpty-million dollars", I'll start worrying about that.