I collect very useful information on text files and stored them in my google drive. with probability of 70% my technical search will find in my directory.
Now I'm looking for a way to search this two resource together (My directory and Internet).
Google has a "Field Trial" that you can sign up for. Currently it combines results from the World Wide Web, Gmail, and Google Drive. The Gmail and Drive results are separated on the page from the general search results, but it only takes a single query to search them all.
This doesn't include Dropbox, however, nor is it ever likely to even if the feature gets generally released.
More details available at Google Search Field Trial.