Originally Posted by Kopsis

There are some 3G wireless services (eg. Freedompop) that will sell you a SIM card ($10 one time charge) that provides a small amount (200 MB/month) of free data service. Pick up a basic used GSM smartphone on Ebay or Craigslist, pop in one of these SIM cards, use any of the free tracker apps, and you're all set up for about $50 and no monthly fees or long-term contracts.