Your last idea seems like the most plausible at this stage. It has the potential to catch on and pass through word of mouth to many online users and businessmen. The advantage being very little marketing money spent to drive up sales.
I'm kind of an idea-man but also very interested in starting a successful business one day, so I'd like to get some honest feedback on some ideas I've had. After a year of work on a failed social network that a friend and I started, I realize now that 1. ideas are a dime a dozen and 2. its best to just go ahead and get your ideas out there to see if they are worth anything rather than building an entire business around a secret idea that noone is ever going to steal anyway.
So, here goes. These are three ideas that you can rip off or just rip to pieces, but I would love some feedback.
Idea #1) After seeing the craze that has built up around social networking, one of the big problems now seems to be that people are conducting all of their communications on a bunch of different proprietary social networks that make money off of keeping you in their network so you can see their ads. But social networking seems so fundamental now to communication that it makes so much more sense to me that a person should just own his own social profile and then these networks would just be the place where you host your profile. My idea is to create a social network that creates a single file that contains all the information about you, your relationships, and your exchanges and then host it openly for you. You could download and host your file with another network at any time. The boon of being the first to offer true user owned profiles would probably be enough to capture a large enough portion of the market to make it worthwhile, much like the way anyone can create a search engine but Google still owns the market. I put together a mockup of how this might work if Google were to do it but I don't think they will anytime soon. http://www.slideboom.com/presentations/49908/Google-Dashboard---Own-Your-Social-Profile
Idea #2) An application that would allow users to shop visually online, without having to read detailed descriptions of every item before deciding which ones to purchase or consume. This one is best explained with a video and here it is: http://vimeo.com/3136826 . This idea is in a very rudimentary stage so I don't know exactly how it could be made into a money making product but it is similar to Cooliris, http://www.Cooliris.com so maybe it could work about the same.
Idea #3) A little application for entering text into a computer by moving your mouse to an area that accepts text input, left clicking, speaking into a headset or mic, letting up, and then the program would enter whatever you said into the text area. It seems like this might be very useful on Android if you just created it as a background app with only a very limited vocabulary for filling out basic forms about yourself online without having to use a cell-phone keyboard. Here is another link with a little longer description: http://sourceforge.net/community/forum/topic.php?id=5055 .
So, these are probably some pretty off the wall ideas but I would really appreciate any feedback you have.