He said that you should test it while dedicating minimal resources. In this case, a Google Doc spreadsheet could do the trick. It's a great piece of advice.
Why spend multiple weekends working on building a prototype when you could start testing the idea's viability (virtually) straight away?
Don't do this: Ask -> "Challenge those with negative opinions"
Do this: Ask -> Consider opinions -> ask more smart questions.
simonw and yoseph are exactly right. They are asking you, "How do you know that this is something people want?" Just because it would be valuable to you doesn't mean it's going to be valuable to enough other people to make enough money for you to live on.
You could find out if you have a market or not by throwing together something really small and simple and using that for a while, or you can find out by building a fancy website and doing everything else you're talking about to make your first presentation pretty, and then a year from now find yourself in the same position you're in now except with less money.
How many people need this?
How much are they willing to pay?
How are you going to make money?
How are you going to reach your market? (Can you partner up somehow with AirBnB or other popular travelers' sites?)
everything else, yeah, i see your point and sort of feel bad. i get what you're saying and it makes sense. i do have an attitude that was trained to challenge negative statements because there's just so much 'this sucks!' on the internet and i always want to understand the motivation behind it.
on the statement of testing viability, 100% agree. asking around here whether you guys know if this will succeed or not is the wrong approach. i should have showed up with the google docs here and asked people to use it please and tell me what i missed. agree.
How about a really simple form that just adds people to a mailing list? "I am in [town]. I would like to receive an email when a visitor is in my area. [subscribe]" ... coupled with, "I am visiting [town]. I'd like to meet people. [send]"
If it stays small, you can manage this manually with little effort, and you'll know that it's probably not a service that lots of people are looking for. If it gets big, you won't be able to manage it manually anymore, but now you'll know whether or not people are interested.
If people have enough of a pain point, they'll happily use a google doc. Look at Craigslist. It's god-farking-awful (worse than a google doc), but people still use it to find apartments...
Let me ask you a question. What is the number one thing you need to test to prove the viability of this idea?
i'll think a bit more about the viability question, it's a tricky and essential one ... the google doc + google form thing could be worth a test...