Not sure exactly what you meaning but if you are speaking of a quick way to text a user.... You have two options.
1. Goto contact name under phone and press the mail icon.
2. Create a shortcut on your home page that links to the contacts and press the mail icon.. Same as first but fast\er.
Handcent has "quick text" messages, but I don't think the generic texting app has any.
Start a new topic or ask questions in the open forum.
