Are there any good webservices for determining the borders of a country/state? I would like to receive an array of points (preferably in JSON) so that I may draw a vector image using this information.
If such a webservice does not exist, where else would this information be located?
There is no such a web service exists. But you can extract this information from Google maps or from any navigation software available on the market. It will require some reverse engeneering, but still possible.
I don't know if there is a web service for this.
However, if you end up having to do this yourself, maybe you're interested in a lovely, freely available geo-database called VMAP0 (Vector Map Level 0). It contains, among other things, national boundaries and coastlines.
(It probably helps if you're familiar with GIS in order to use the data.)