Count number of results for a particular word on Twitter

Question

To further a personal project of mine, I have been pondering how to count the number of results for a user specified word on Twitter. I have used their API extensively, but have not been able to come up with an efficient or even halfway practical way to count the occurrences of a particular word. The actual results are not critical, just the overall count. I'll keep scratching my head. Any ideas or direction pointing would be most appreciated.

e.g. http://search.twitter.com/search?q=tomatoes

Answer 1

I'm able to go back about a week. I start my search with the parameters that Adam posted and then key off of the smallest id in the set of search results, like so, http://search.twitter.com/search.atom?lang=en&q=iphone&rpp=100&max_id= where max_id = the min(id) of the 100 results I just pulled.