[fywacro]

Depends on what you mean by realtime. In most cases (stats-wise, anyway) analyzing a non-stored infinite-length data stream is a very different challenge from analyzing a stored, finite-length data set.

Streaming algorithms do exist for many basic statistical measures. But in many other cases, the best streaming algos aren't cheap or accurate enough to be useful.

Bucketing can sometimes substitute for a bona fide streaming algorithm. But again, there's plenty of cases where bucketing won't work well enough to make it useful.

I haven't really looked at Statwing yet--the premise is really tantalizing, though. Gotta find an excuse to throw a spreadsheet in there and see what comes back.