I frequenlty use Gespeaker to paste a phrase (using select to copy, and mousle middle-click to paste) from clipboard to hear pronounciation of words.

I think I'd would be good to have a button that would clear the textbox instantly, as right now I have to manually backspace all text I had there before I can proceed (selecting it would replace my clipboard content that I want to hear).

This feature could maybe satisfy my need:

http://code.google.com/p/gespeaker/issues/detail?id=18