nueMMS will let you send MMS over e-mail, so you won’t need an MMS gateway to send MMS. It supports several providers/carriers, and you can add more carriers in carriers.nuemms – its a simple xml file. It also supports sending your gps coordinates over mms (..kind of untested, but give it a shot).

http://forum.xda-developers.com/showthread.php?t=372302