I have been working on Google API’s for some of my personal projects and found it both really easy to use and quite straight forward. Specially when it comes to User Authentication and also with Geo Tools. Or if you plan to use it to embed social communities like orkut, into your own applications.
So far i used only 2 of them and it seems be great
- Use Gmail Authentication for your user application
- Google Maps (road) for your locations
Those who want to try them .. visit it here
Obviously yes! Google has some nice set of APIs, tried few, more are worthy of exploring as well.
I tried the translation API, was pretty good as well.