Twitter, a microblogging service in which millions of people post brief text messages, has emerged as the custodian of a valuable online index of real-time facts, comments, musings and announcements, information that is clearly valuable for Google's search engine index.

Google routinely collaborates with major Web sites to determine the best way to crawl and index their content for its search engine, so sitting down with Twitter for that purpose would be consistent with its modus operandi.

"Twitter is clearly hot. The phenomenon of real time search and the ability to capture this stream of 'tweet' discussions is an important development in social media and search because people are trying to mine data for information that might otherwise be sought in a search engine," said industry analyst Greg Sterling from in a phone interview. "This whole phenomenon Twitter represents is here to stay and needs to be addressed by search engines."

However, it's much less clear why Google would want to spend major-acquisition money on Twitter at this time. After all, Twitter doesn't represent anything close to a clear and present danger to Google in the search market. "Twitter exemplifies the category of real-time search, but it's not a Google killer," Sterling said.

In addition, Google, like most companies, is in cost-cutting mode and Twitter, while wildly popular, hasn't figured out a way to generate much revenue yet.