text in top (status) bar

Some apps (notably Lookout Mobile Security) show a text describing action done for a short time (maybe 1 sec only) on the top (status) bar and then the display goes back to the regular 开发者_JS百科status bar (with a nice animation effect at least on HTC phones). How is this done ? I am not talking about notifications !

This is actually part of the Notification. It is called the tickerText. See:

http://developer.android.com/reference/android/app/Notification.html#tickerText

And, if developing on HoneyComb:

http://developer.android.com/reference/android/app/Notification.html#tickerView

You can also pass the tickerText into the constructor of the Notification.

I think the function Activity.setTitle() is what you're looking for.

Edit:

Or, you could produce a custom notification that only appears for one second.