Usually following an exhastive web search including on Halfbakery itself and then after forming my idea in words at length on this site, I usually make one last search with some new keywords that cropped up and find out that the idea or solution I want to make or do already exists.
So all that is needed is an extra sidebar on the right with results of accumulated search terms while I'm typing, say every five words.-- pashute, Oct 13 2015 It's been done. HalfBakedery [the porpoise, Oct 13 2015] I assume this would work on any page where you're typing into a text box. So as you're typing an email about how your basement just flooded, you see links popping up about the best way to clean up a basement.
Or you could just have it look at the full text of the current page (including text boxes) and give "related pages" links.-- scad mientist, Oct 13 2015 Sorry [pashute], it's been done. See link.-- the porpoise, Oct 13 2015 random, halfbakery