Spotty Process: Current cheapest price for a give instance type

response.js

// Request using availability zone codes
// curl http://spot.arfon.org/cheapest/m1.large
// Example response below

{
  "linux": {
    "availability_zone": "us-east-1a",
    "current_price": 0.026,
    "id": "50b196d2a2fc8eef1000004d",
    "name": "m1.large",
    "pricing_history": {
      "2013-01-04 19:36:12 UTC": "0.026000",
      "2013-01-05 19:36:13 UTC": "0.026000",
      "2013-01-06 19:38:22 UTC": "0.026000"
    },
    "product_description": "Linux/UNIX"
  },
  "windows": {
    "availability_zone": "us-east-1d",
    "current_price": 0.066,
    "id": "50b196d2a2fc8eef10000048",
    "name": "m1.large",
    "pricing_history": {
      "2013-01-03 21:11:59 UTC": "0.066000",
      "2013-01-04 21:15:06 UTC": "0.066000",
      "2013-01-05 21:17:12 UTC": "0.066000"
    },
    "product_description": "Windows (Amazon VPC)"
  }
}