Our community allows golf carts on the public roads to reduce pollution and congestion and my mother uses hers extensively. Golf carts don't have much in the way of security, so for peace of mind, I thought I'd roll my own vehicle location system. This has been done many times here on instructables and on other sites, but I'd like to think this version is the simplest and neatest, both in software and in packaging. I'd also like to think I'm charming, witty and intelligent...
I had considered using amateur radio, but the cheap Baofeng radios I had on hand were unsuitable for packet operation. So, if I had to buy new equipment, I might as well look at cellular. With the local Radioshack blowing out a lot of 'hobbyist' electronics, the GPRS Shield was selling for about $15 less than buying direct from SeeedStudio. So I went ahead and picked up a shield (or 4 so I could use them in future remote projects). With a little bit of shopping, I came across H2O Wireless with 200 SMS messages for $10 prepaid and they last for 90 days... or about $40/year with each message sent or received costing five cents. This was plenty for something that should rarely be used and if I burned up a bunch in testing, it was cheap and easy to refill over the we