I will suggest a few modern day scuttlebutt methods here.
First, Google Trends, which indicates the volume and frequency of search terms relative to the total search volume across region and time, is helpful in gauging consumer demand. For example, it will be useful to compare the volume of Google searches generated for competing smartphone models such as iPhone 5 from Apple (AAPL) and the Samsung Galaxy Note 2 from Samsung.
It is interesting to note while the iPhone 5 generated significantly more search volume than the Galaxy Note, the search term Samsung Galaxy got more search volume than the iPhone 5. We can infer that while Apple may sell more iPhone 5 handsets than Samsung's Galaxy Note 2, Samsung will sell more handsets in the Samsung Galaxy series (Samsung Galaxy III, Samsung Galaxy Note 2, etc.) than iPhone 5 handsets. Google Trends works best for consumer discretionary products, where consumers will make efforts to research on the products online.
Second, online job sites can provide significant insight to personnel movement and new areas of business growth. Although companies are required to disclose the hiring and departure of key personnel such as the CEO and the CFO, there are other key appointment holders such as the head of sales, the chief technology officer and other division heads. I can give a few examples here. If five finance managers are hired in three years and the finance manager reports directly to the CFO, it could be a warning sign of fraudulent accounting practices.
In another example, a company is hiring aggressively in Asia, where Asia used to contribute only less than 5% of revenues, it could signal a shift in the company's geographical focus. Although most companies put up job ads without disclosing themselves, the company description will usually provide enough clues to those in the know.
The last method is slightly more controversial, as it borders on the invasion of personal privacy. Social networks like LinkedIn (LNKD) and Facebook (FB) could provide unusual insights into a company. If you are interested in whether more ex-Google (GOOG) employees are joining Yahoo (YHOO) as a result of Marissa Mayer's connections, LinkedIn profiles could provide you with the answer.
I could provide another more bizarre and extreme example. A mid-level Facebook employee could post on his Facebook's wall that he is planning a year-end celebration with his wife, as he expects a huge bonus this year.
There are numerous ways to implement modern-day scuttlebutt methods and I appreciate interesting suggestions from readers in the comments section.