Thousands of Twitter messages carrying the words "gmail" or "gfail" will teach you that Google's free web-based e-mail platform is currently down. A Google spokesperson told Pocket Lint that their engineers are working on it but have no clue why the errors are turning up.
Meanwhile, Google posted this on a discussion form:
We're aware of a problem with Gmail affecting a small subset of users. The affected users are unable to access Gmail. We will provide an update by February 24, 2009 6:30 AM PST detailing when we expect to resolve the problem. Please note that this resolution time is an estimate and may change.
(POP3 / IMAP seems to be still functioning, and the problem doesn't appear to affect Google Apps at this point)
I'm not buying the small subset part, and considering the fact that Pocket Lint says the problem started occuring around 10:20am GMT, 3 hours before even telling everyone what's going on is an incredibly long timeframe in my opinion.