There is a new shared block on Popfly called Locust IP Locator courtesy of mois. I thought I'd detail how I built it. First of all, download the block SDK, read the Building Blocks guide, and look at the samples once you start going. It's really helpful to see what the XML looks like, and how it maps...

I created a really basic web service that performs an IP geolocation based on the database at http://www.hostip.info . All it does is construct and hydrate a serializable object with string properties based on the IP you pass to it. Be careful because I was pretty lax on error handling this time around...