Bogdane ne slusaj sta ti govore :-)
I disagree that "ideas are worthless" and execution is everything. It is often repeated in our industry but only because there are so many people around who never had a good idea nor are they analytical enough to understand it even after it happens in real life. I remember multibillion dollar presentation from the time I was working at Goldmans with a slide titled "Past performance is not a guarantee of future returns, but what else have we got?". Scary...
The fact is that there are tons of more people who could do good execution or get resources via funding, but this life doesn't work that way otherwise richer would get richer, bigger companies bigger and there would be no successful startups.
If analogy is made between a car and a business you could say that engine is an idea and execution are wheels. You need wheels to move but the engine provides necessary acceleration which is the key in today's economy. The ideas are key and they are the ones propelling us in the future. We should not be like parrots repeating "you need wheels to move, you need wheels to move".
The simpler idea is, the harder it is to get to, and more valuable it is.
Regarding an NDA you should always include a subject line about the topic you are about to disclose and it should not describe precisely crux of your invention. For example, you could say "System and method for kids’ stimulation of learning by using internet connected devices" It does not include how you have solved the problem but at the same time your potential partner would know if what you are about to disclose is in conflict with something he/she is already doing, and if that is the case they should be honest with you and either not sign because of conflict of interest or not do it on their own as it is a very specific legal document.
However, if you need much greater protection from e.g. reverse engineering after you have launched your service and it is in public domain and/or protection from other competitors and your idea is significant than you should apply for a patent application. It is not too difficult to do and you could do it yourself from free. You will be much more protected for one year in which you have to decide if you want to invest in your patent protection or dump it.
There are many examples out there but I will give one, and that is of Larry Page whose idea was about importance of hyperlink in search engine algorithm. After they proved value of it in the market, others such as Overture and Yahoo multibillion dollar valued companies at the time with huge resources, execution capabilities and market interest, could only watch their value evaporating in front of their eyes.
Having said that there are many businesses doing well with no patentable ideas e.g. foundersdating.com and they are doing well, but if Larry listened to some of the advice from people above in 1996 and did not sufficiently protect his idea we would not have Google today as we know it.
Filter out noise from your advices and think what kind of idea is yours and what kind of protection do you need.
If you need help with an NDA or initial patent application, don't be shy and get in touch.
Maybe I should start a blog on this subject. :-)