Real-time microblogging and messaging services like Twitter could potentially become a threat to Google -- whose search index doesn't keep up with conversations as quickly as Twitter's. So what does Google (GOOG) CEO Eric Schmidt think about Twitter?

"Speaking as a computer scientist, I view all of these as sort of poor man's email systems," he said this afternoon at Morgan Stanley's technology conference. (Live notes here.) What's he talking about?

"In other words, they have aspects of an email system, but they don't have a full offering. To me, the question about companies like Twitter is: Do they fundamentally evolve as sort of a note phenomenon, or do they fundamentally evolve to have storage, revocation, identity, and all the other aspects that traditional email systems have? Or do email systems themselves broaden what they do to take on some of that characteristic?

I think the innovation is great. In Google's case, we have a very successful instant messaging product, and that's what most people end up using.

Twitter's success is wonderful, and I think it shows you that there are many, many new ways to reach and communicate, especially if you are willing to do so publicly."

Schmidt also plugged Google's new Twitter account. But he flubbed Twitter's famous 140 characters-per-message limit in the process, describing @google as a place to "go ahead and listen to our ruminations as to where we are and what we're doing in 160 characters or less."