chronster - from the sounds of it, looks like you might be interested in this:
http://www.nvcnow.com/nvc1/Index/index.htm
I use this on a daily basis. It allows you to press a button, record a SMS, compose an Email, add Appointment, Web look up and call a contact or look up a contact and translates it into text so you can send if you were blind.
The text and email is limited to about 20-25 words, but for texting and short email works like a charm. Great for when you are on the road. I usually only use this as opposed to typing.
On the website under device look up, it only lists the 6700 and 6800 (mogul) but it also works with the Sprint Touch Pro. You have to use AE Button and assign the application to a key so you can hold it down to record your Text or Email. I set it up to use the enter button. Again, works great on my device. There is a monthly service charge of 5.99 per month, but to me that's worth it. Saves me alot of time and head aches of typing the message. Not to mention the risk of getting in a head on collision.
Check it out and see if it's what you are looking for. Best of luck!