Ask for money before having a prototype?
brk: It would likely depend on the scope and scale of the idea, and how you go about proving that you can be successful at implementation.If your idea is geared around a web-app, your chances are probably pretty small.  It's easy to put together the basics of a demo, and anyone who did not put in that minimal effort would likely be met with skepticism.If your idea is something like a complex new mesh networking algorithm and chipset... well, most investors wouldn't expect you to have developed a new ASIC out of your own pocket ;)  However, you would likely need a very solid track record in the technology and other applications of it (eg: work at another company, research lab, etc.).