Tracking the reception to Google’s second day of announcements was best done by closing your eyes, and listening for the sounds from the roughly 5,000 assembled developers in the theatre at the Moscone Center, San Francisco.

Relieved applause greeted the announcement of a new version of Google’s Android mobile phone platform, called FroYo for Frozen Yoghurt or more simply Android 2.2, as the expectations of the developers were confirmed by Vice-President of Engineering Vic Gundotera. Minutes later the room erupted into wild applause and hollering with the news that it will be possible to tether Android devices to act as 3G modems, and also to use them to create wireless hotspots.

Gundotera kept the crowd noisy by announcing that phones receiving the Android update will see a 2-to-5x speed increase in all apps, thanks to tweaks to the platform’s base, and by revealing that a beta version of Adobe’s Flash will run on FroYo. He also earned laughs with a string of jibes at Apple, whether pitched at the iPhone’s inability to multitask, or in the form of a demo that showed the iPad’s browser couldn’t muster the javascript speed to display a robot swimming laps of a pool as fast as a Nexus One phone.

Speaking after the keynote, though, Gundotra emphasized that Google continues to work with Apple in many areas, adding “my talk is available on YouTube… I’m sure we’ll hear from him [Steve Jobs].”

When using the eyes-wide-shut method, spotting talk of where the money to pay for all these new toys comes from is a matter of listening out for silence. The devs were quiet as Gundotra talked of new forms of advertising for Android. Text ads will appear inside apps based on their content, business will be able to place “click to call” ads to people nearby, and more traditional display ads that expand over an app will also appear.

The devs woke up again for the second big announcement of the day–Google TV. Senior product manager Rishi Chandra warmed up by pointing out that the average American watches 5 hours of TV a day, feeding an advertising market worth $70bn a year, and then earned applause of his own by introducing a big Sony TV to demonstrate the new Google TV platform. It will, says Chandra, offer the “best of what TV has to offer today, and the best of what the web has to offer today.”

With a chip inside provided by Intel the TV is controlled by a wireless keyboard. Users can type to search TV shows by name or topic, and receive results that mix live TV broadcasts, future broadcasts that can be set to record to DVR with a single click, and web content such as YouTube videos and other Flash content.

From this Fall both Sony’s new TV’s and settop boxes made by Logitech will be available in Best Buy stalls, a schedule intended to surf the seasonal wave of gadget buying. The Google TV platform runs on a version of Android, and will run cellphone apps as well as customized TV-centric applications.

Google CEO Eric Schmidt appeared at the end of the keynote with a parade of fellow CEOs. His gentle chat with the leaders of Best Buy, Sony, Logitech, Dish Network, Intel and Adobe was a reminder of how important third party support will be to Google in the storied world of TV, and there are many questions still outstanding.

One is whether domestic broadband circuits would stand up to large numbers of people streaming high quality video for hours a day, another was what progress is being made on making agreements with content providers. Hulu for example, is a web catch up service operated by TV networks to complement their traditional services. How will they feel about the prospect of it being seamlessly available on TVs? Eric’s new friends are a start, but more will be needed for Google TV to deliver on the promises made today.