Unemployed but with ideas burning a hole in my brain. Where to?

(Incoming wall of text)

I'm a 27-year-old recent college (under)graduate (computer science) who's currently unemployed and having a heck of a time finding a job. I have what I believe is a decent résumé and I'm certainly intelligent and talented, but companies keep passing me over for people with more experience. This is incredibly frustrating because I make it to the final round of interviews and things appear to be going absolutely great - I like them, they like me, they're impressed by what I've said/done, and then fwoosh, I don't get the job (and apparently a lot of my peers are having the same problem, including those who are far better developers than I). I can't even get jobs that I'm significantly overqualified for because employers can tell that I have actual career goals and won't be happy in an entry-level position for 5 years.

On the other hand, I've had a few ideas burning holes in my brain for several years now. The types of ideas that keep you up at night and fill notebooks with scribbled notes and thoughts. The types of ideas that start with that programmer who wants to satisfy an itch or knows they can do better than some existing and popular software.

I have one fairly developed idea in particular: an alternative to an extremely popular website that has a near-monopoly, but everyone I've talked to seems to unanimously agree that it's terrible and they only use it because they have no other choice. I've talked about it at length with some folks, and all have been excited about my ideas for it.

Here's my dilemma: I need a job NOW. I needed one many months ago, actually. My savings are nearly gone and I need to pay rent. However, I'm having this bizarre and unexpectedly difficult time finding one. I've also always known that I want to create my own software startup (although I learned not to mention that at job interviews a long time ago ;), and lately I've been thinking about it more and more and reading everything I can about it, and it actually seems feasible.

One of the things that has always held me back was the feeling that I needed to fully plan out the project from start-to-finish, have every feature designed, a working prototype, and a precise-down-to-the-color-of-the-carpet business plan before I could even THINK about approaching investors for starting capital. However, this is a rather non-trivial project that will require quite a bit of research and user feedback before I can write a requirements spec for it. It seems I can't do that without having an already-funded startup.

Obviously, I can't be looking for a job AND planning out a startup. Both are more than fulltime tasks, and I can't really afford the time to put a lot of planning into a project that may never even get a dollar of funding. It's also most definitely not something I can do myself - I estimate I would need at least 5 people working with me (3 of them developers, myself as CEO and project manager), and it could take anywhere from 6-10 months before a beta/significant version could be released.

Long story short, is it even the least bit reasonable to be thinking about a startup now? Is it actually even possible to get non-friends-and-family funding in a timeframe shorter than my nearly-gone savings will allow? Am I too "inexperienced" for investors to be interested in me? Should I just can the big ideas for now and nod and say "Yes, sir" and take any job I can get? Or continue along on my path of doing more and more for each company I apply to and continue aiming for my ideal job until I get it (apparently not working so far)?

Thanks if you stuck with this and read the whole thing - I really appreciate it. I also just discovered this site, and I love all of the beta sites StackOverflow has out!

1. Get a job now to pay the rent. Take whatever you can get.
2. If the job you find doesn't allow you to work on an outside project, or is too big of a step down because you were desperate, look for a new job next.
3. Work on your project after hours. Your rent will be paid, and should you fail, all you lost was a lot of free time. But you will also gain a lot of experience, and many people have to fail a few times before succeeding.

Obviously, I can't be looking for a job AND planning out a startup. Both are more than fulltime tasks, and I can't really afford the time to put a lot of planning into a project that may never even get a dollar of funding. It's also most definitely not something I can do myself - I estimate I would need at least 5 people working with me (3 of them developers, myself as CEO and project manager), and it could take anywhere from 6-10 months before a beta/significant version could be released.

You've thought through what it would take to replace the sucky near-monopoly, and you've recognised your own tendency to over-engineer. So here are some choices:

1. Distil down and down until you have a project that you could execute on and that would validate your core assumption (that the incumbent's user base would readily move on)
2. Pitch your idea not to prospective investors, but to prospective co-founders. You can't fail to learn from the experience.
3. Search for an idea you could execute on your own. Be disciplined and systematic. Choose a field where you understand the technology and know how to reach the users, find a problem that's already being expressed, and set out to solve it well. If you develop a range of good ideas, choose the one you judge minimizes your time to market and maximizes direct monetization.
4. Look for a startup looking for someone like you, and where the team are making ends meet other ways.

You can make time for this. Think through the options. Talk them through or try them for size. Choose. And follow through.

Best of luck!