If you are within wifi range and make a text message, are you using your data plan or is the phone using wifi? I'm a little confused with this so far. This is my first data phone so I'm unsure of how it works completely. Also, if you are not within a local tower as I work offshore but we have wifi. Can I use the wifi to send text messages and phonecalls? Software for phone calls? software for txt messages. So far I have Handcent SMS for messaging.