[teraflop]

Doing it with a low false positive rate (so that you can enable it for everyone without being annoying) is much harder.

Also, Gmail has lots of users who speak languages other than English... has anyone tested whether the forgotten attachment detector works for them too?

[duaneb]

Pretty sure it looks for the phrase "attach", it doesn't appear to be super sophisticated. Either way it works well.

[leni536]

It sure works for hungarian, as far as I remember it doesn't catch all synonyms of "attach".

[sdrothrock]

It works in Japanese, though with more false positives than in English, I think.