I have some custom text substitutions set up in the Language & Text pane of System Preferences. But in order to activate a substitution, I have to type the shortcut and then press the spacebar. This results in the replacement text followed by a space character. So if I want the text to be at the end of a text field when I submit a form, for example, I have to type "[shortcut]space⌫↩" instead of just "[shortcut]↩".
Is there any way to make the replacement instantaneous, so I don't have to insert and delete a space that I don't want?