Good searching. Looks like you've found quite a few more vulnerable sites too.
I would wager to say a large majority of .asp sites out there are vulnerable to these types of issues.
Most were coded before common sanitization and security practices were observed during dev, not to mention built in to frameworks.
It was a map of Thailand, so that gave me the type of restaurant. From there it was just a simple Google query combining that knowledge with the URL structure revealed in the blog post:
http://www.google.co.uk/search?q=thai+restaurant+locationid%...
Then it was just a case of working through the list of possibilities (it was second on that list) :-)