"The Google Web APIs service is made available to you for your personal, non-commercial use only (at home or at work). You may only create a single account and must provide accurate identification, contact, and other information required as part of the registration process. You may not create any script or other automated tool that attempts to create multiple Google Web APIs accounts. And you may not use the search results provided by the Google Web APIs service with an existing product or service that competes with products or services offered by Google.
If you are interested in doing anything different than the foregoing, you must first obtain Google’s written consent. If you fail to do so, Google reserves the right to take legal action against you."
03/18/05 update: Google Code.