You can send picture messages to other phones, but you must do it through email on the Q. You can send it to their provider's MMS mail address. I've included a few below. In all cases, replace TDMN with the person's Ten Digit Mobile phone Number.
Alltel -
TDMN@message.alltel.com
AT&T -
TDMN@mms.att.net
Cingular (AT&T) -
TDMN@mms.mycingular.com
Sprint -
TDMN@messaging.sprintpcs.com
T-Mobile -
TDMN@tmomail.net
US Cellular -
TDMN@mms.uscc.net
Verizon -
TDMN@vzwpix.com
Hope these help.