I actually thought about autotext before I wrote my own software (TextMob: http://wireless.sra.com/utils/)
. The problem in this case with autotext is that you can't ask AutoText to insert details from the email. If you simply wanted to paste in a set text, with no substitutions, you'd be fine.
What I was looking to do was to put email-specific information into the outbound message. For example, have a template that would substitute in the recipients name, so it is more personal.
I looked at BB Response, and as you can see above, I didn't go for it because it wasn't free for personal use. BB Response may very well be excellent software, it just wasn't ideal for me.