Here is archive of sorts - http://www.oppslist.com
The ideas are of a mediocre quality, but I find they help stimulate thought.
Another idea is to go to a place like Fiverr and look at which services are most widely bought. Then build a saas solving one of those problems.
How can someone follow this list? I'd be interested in following and possibly knowing which are new when I come back.
And the opportunities listed all seem at least a year old. That's not very "new", is it?
I personally tried out an outsourced sales venture based on one request. I made around 1k in revenue the first month doing that. I found that my overhead was high and it was a competitive landscape to find clients.
At this point in time, I'm just playing the messenger. I'm not trying to get people rich. Although, I think in the future that may be a metric I start to measure myself by. Hope this helps :)