Google long-undead SOAP API is still in that state, but now there is a new (apparently) REST API with JSON output.
Details at http://code.google.com/apis/ajaxsearch/documentation/#fonje in the "Flash and other Non-Javascript Environments" section.
Their description:
"For Flash developers, and those developers that have a need to access the AJAX Search API from other Non-Javascript environments, the API exposes a simple RESTful interface. In all cases, the method supported is GET and the response format is a JSON encoded result set with embedded status codes. Applications that use this interface must abide by all existing terms of use. An area to pay special attention to relates to correctly identifying yourself in your requests. Applications MUST always include a valid and accurate http referer header in their requests. In addition, we ask, but do not require, that each request contains a valid API Key. By providing a key, your application provides us with a secondary identification mechanism that is useful should we need to contact you in order to correct any problems."
This puts things on even footing with Yahoo!'s excellent API.
"You agree that you will not, and you will not permit your users or other third parties to: (a) modify or replace the text, images, or other content of the Google Search Results, including by (i) changing the order in which the Google Search Results appear, (ii) intermixing Search Results from sources other than Google, or (iii) intermixing other content such that it appears to be part of the Google Search Results; or (b) modify, replace or otherwise disable the functioning of links to Google or third party websites provided in the Google Search Results."
With those restrictions, it's really more of a widget than an API...