What does the @twitter tag do?

macman,

If you have Twitter configured on your Sandy account (see http://iwantsandy.com/settings/twitter), you can use the @twitter tag to override your default reminder settings.

If you don't usually want to be reminded via Twitter, you can turn Twitter reminders off in your settings. Then, tag something with @twitter to have Sandy remind you via Twitter just for that event.

Similarly, @email and @sms override your default reminder settings for those as well. If you say "remind me to move the car @twitter", you will only get a reminder via Twitter. If you say "remind me to move the car @email @twitter", you will get reminders via email and Twitter (but not SMS).

Hope this helps,
Marshall