I, too, am sole developer on two huge projects. What you describe happens to me sometimes, too. I'm assuming that you're referring to those "stalls" that can last for days, and not simply battle fatigue.

I have found that the following things help me:

1. Pick out something very small and very simple to accomplish, and do it. Don't worry if it's not on the mainstream of the effort. What's important is to move forward. That relieves some of that horrible inner pressure that builds up when stuck for too long.

2. If that fails, try creating on or more small experiments for yourself, regarding things that you're curious about or things that have been particular troublespots. These can bring great joy and release the flow for you.

3. If these things fail, be productive doing something else altogether. Don't worry about wasting time, because you weren't moving forward anyway. This, too, can start a flow.

Remember, friend, that in a time of famine, a small harvest is better than none. Do not despise small accomplishments.

Peace---

We should have exhausted this question when cigarette companies were caught enhancing nicotine levels in their product, in order to increase addiction, which enhances profit.

Consumers must have the opportunity to make conscious choices and give informed consent when consuming anything known (or reasonably suspected) to be habit-forming. I have no desire to form a nanny state, but folks need to know what they're getting.

Human nature being what it is, this is an excellent opportunity for black market corruption -- drug company sells to developing country. Corrupt elements in developing country sell back to corrupt black marketeers who then resell in 'rich' countries to corrupt vendors for reduced prices and still make huge profits.
And still the people who need the drugs don't get them, but maybe some actually will, and that's a good thing.

The scenario I saw play out is admittedly far-fetched but as a Slashdot reader, I've come upon shocking articles regarding our infrastructure here in the US being targeted by hackers from inside Russia and China. Here's one such example:

http://technology.timesonline.co.uk/tol/news/tech_and_web/the_web/article2409865.ece

Now let's do a bit of extrapolation:
1. widespread adoption by NYC & LA -c class municipalities
2. traffic signal control governed by this 'network'
3. Understanding of the architecture gets into the hands of even more virulent enemies.

These three steps are not unlikely should this technology prove to be effective and become popular.

Now consider this scenario.

It's a day with fairly good weather near the Holiday shopping season. Commercial activity is at it's peak, along with tourism. A physical attack is then initiated along the lines of a medium sized chemical or biological weapon, or perhaps bombing of a central municipal structure such as Grand Central Station in NYC. Coordinated with this attack is a simultaneous assault on the traffic control network. This attack makes it impossible to
a. escape the scene
b. get first-responders to the scene

Result: complete chaos and panic.

The increasing tendency to use this type of communication to support critical infrastructure is an open invitation to chaos and disaster induced by malicious hacking.

Consider for a moment all the past reports of external hacking on U.S. infrastructure and the chaos they created. Now imagine what would happen were this to be hacked after widespread adoption.

You all very well know that from the moment of its inception there will be concerted efforts to do just that.

No thanks.

Leave out the networking with private vehicles and it gets a bit better, but there's still a vulnerability.

Again, no thanks. It can't be made hacker-proof.