[sushi]

I have personally loved sites which have tried to utilize the "intelligence of masses" and wikipedia being the prime example of that. Similarly Hacker News, Reddit, StackOverflow and many others which excite me the most.

1) I think I'd love a much better way of finding homes/real-estate which can derive synergy from 3rd-party apps like Google Maps as well as bring about some kind of social features more in the line of commenting we see on HN.

2) Mentioned earlier.

3) I think one can see huge opportunities in B2B niches. There seems to be a great unfilled opportunity in bringing together the businesses. The thing is that most of these businesses don't understand anything about web or Google Adwords which they might use to better market their products. The idea is to make it extremely simple for them to find other businesses which might be willing to buy the products and services.

[adam_albrecht]

I've been consulting (as a software developer) for a large home-building company for a while now and this experience has given me quite a few ideas and insight related to your #1. I'd be curious to hear you elaborate on this a bit more. Billions and billions of dollars go through this industry every year (even when it's down) and yet, the industry as a whole doesn't understand the web. So there are plenty of opportunities.

[jeffepp]

There is a lot of room in real estate -- from getting a mortgage --> finding houses on the multi-list.

I ended up getting my real estate license about a year ago just to not have to deal with agents (I have flipped a few houses). They were so inefficient it literally was painful.

[dreepers10]

Maybe like zillow, combined with Bing 3D maps, but with comments?