You will not and will not allow on your behalf third parties to (a) make and distribute copies of any aspect of the iGoogle page (including the API) or accompanying documentation except as permitted by these API Terms and Conditions; (b) attempt to copy, reproduce, alter, modify, reverse engineer, disassemble, decompile, translate, or attempt to discover any prototypes, software, algorithms, or underlying ideas which embody the iGoogle page or Google API;...
The Netvibes UWA, seems like a decent response/alternative gadget API. However, it seems pretty much dead since its release in April. It also doesn't have a specific license or terms associated with the UWA API Documentation itself.
All I want is a public and open API for developing widgets and gadgets against. Sigh..