Panayotis Vryonis has put together a great Google tool: g-metrics.com. It allows you to give a number of search terms, and track the # pages found by Google for each over time. ( The
'Results 1 - 10 of about NNN for xyz' line above every search) See the example for ‘linux’ left of this text to get an idea.
A simple idea, but very well done. If he is using the Google API, he probably cannot go over 1000 keywords, except if he’s going to use multiple license keys, which is not really appreciated by Google. The g-metrics service is currently free.
Suggestion: Panayotis, could you make something similar for Google PageRank? You don’t need the Google API for it, you just have to calculate the checksum for each request.