Coming from the iPhone I thought it was cool that you can speak an MMS message. I think you have to have Handcent MMS. Just click in the area where you would normally type a message and hit the MENU then SPEAK. Just say what you want like - BE HOME LATE and voila - the text appears in the MMS area and just hit send. I did not see that option under the built in Messaging app.
Sorry if this is old news. Kinda cool.