Way back, one of our readers begged for an iPhone LoJack solution. He wanted his iPhone to "call home" regularly in case of loss or, let's be more realistic, theft. Over the past week, I finally had a chance to give this request some time, and I put together findme. It's a command-line program that returns the location of the cell phone tower nearest to your iPhone. When run, it tells you the tower id, plus its latitude and longitude courtesy of Google Maps.
Still, how to get the location report to a place you can get it... but nobody else can... and without receiving a zillion SMSes? For this part of the puzzle, enter Twitter. Twitter dev Britt Selvitelle helped walk me through the setup for a private account that allows your iPhone to phone home but keeps the location data relatively secure.
To do this, create a new Twitter account just for your iPhone (it will need its own unique email address, separate from your main account, so have one handy). Open the Settings panel, and look for the "Protect My Updates" checkbox. It's towards the bottom of the page, just above the Save button. Check this and click Save. With protected updates, only the Twitter users you approve will see the updates for this iPhone-only account (just you? you + spouse? spouse, kids, and "special friends?" Up to you).
Update: I've put an updated version of findme (findme-better) into the TUAW folder on my site. Please let me know if this works better for location for you. To use, just copy to your iPhone (you may have to use Firefox if you get errors after downloading with Safari), rename to "findme" and replace the original findme.