Google today is expected to announce Gmail Chat, a program that will let Google e-mail users instant message each other online. Google's e-mail service is the fourth most popular on the Web, but lags
far behind the three market leaders--Yahoo, AOL, and MSN Hotmail, according to Nielsen//NetRatings. Gmail last month had 6.7 million users, compared to Yahoo Mail's 50.7 million, AOL's 34.3 million,
and MSN's 31.3 million. AOL's instant messenger was the most popular IM service, wtih 52.8 million users--followed by MSN Messenger, with 27.2 million, and Yahoo Messenger, with 21.8 million.
