Is there any way to hide your phone number or call back number when sending a sms text message?

Wirelessly posted (8120 4.5.037)

Through a few online services yes but not via your BlackBerry. And the ways to do it online they can not reply so pretty useless.

this ticks me off with my sprint. my callback number always shows. kinda annoying but not really a problem. if i delete it, it coms back wheni restart the phone