What webservices do you use regularly and which do you wish were available?

Question

I know that the USPS provides an handy XML over HTTP webservice for address information. What other webservices do you know of and use? What webservices do you wish you could access but can't find?

Answer 1

I've used geocoding services from both Google and Yahoo to find lat/long coordinates for cases that I post on my web site. (I use both because I've found a number of cases where one can find a place and the other can't. Since I geocode interactively as I prepare the data for the site, its easy enough to have both available and try each out as needed).

I'm not sure you'd call it an XML-over-HTTP service since what it returns is not XML, but I like the Google Static Maps API as well. I use that to create those thumbnail maps you see on my site. Very simple, you cram everything you want into the URL and HTTP returns the graphic file as the content body.

Answer 2

This one's pretty simple, but Google hosts all the major JavaScript libraries along with an efficient way to import them. Assuming people use it, it's more out of the cache. You should probably check that the files exist before relying on them without a backup plan, though. I don't trust Google that much.

Also, could you link up to the USPS utility?