News, Twitter, conferences, VC advisory board members, independent consultants, university professors. Everyone likes talking to VCs and telling them what the h

News, Twitter, conferences, VC advisory board members, independent consultants, university professors. Everyone likes talking to VCs and telling them what the hot tech trends are. There's also public funding sources and scientific conferences or publications that will identify upcoming technologies a couple years before they are VC-ready. Finally, "what's new and hot" is not really sensitive information. You have to get pretty deep into a company's business before you run into something that's confidential.