(Non-Jailbreaking Method)
I'm trying to replicate many of the MobileMe functions using free alternatives, like Google Sync for Contact/Calendar/Email. Storage is being handled by Dropbox as a replacement to iDisk and allows me to delete my important data should it get stolen.
However if someone knows how to ping/email/call my iPhone (3GS) remotely and get a GPS fix I would be interested to hear about it.