Erica Sadun of iPhone coding fame just rigged up a sort of LoJack for your jailbreaked iPhone. Using Twitter, the iPhone can send periodic updates telling exactly where it is in terms of the location of its nearest cellphone tower. If your phone is lost or stolen, just check the Twitter update page and grab the latest latitude and longitude, which you can then use to somehow track down your phone. We're not sure how well it'll work in practice, but it's better than nothing. [TUAW]