Google's I/O 2011 developer conference has seen the company talking about its Android mobile platform.

It says there are now 100 million activated Android devices around the world, with 400,000 new Android devices activated every day. The Android Market has seen 4.5 billion downloads and currently has 200,000 free and paid applications available.

Motorola Mobility Holdings has released its first quarter results for 2011. Revenue was up 22% year-on-year to $3.0 billion, with the mobile devices part of the business generating $2.1 billion. It's still losing money but overall losses were down.

The company shipped 9.3 million mobile devices during the three month period, including 4.1 million smartphones and more than 250,000 XOOM tablets.

This week's news stories include claims of spying iPhones, Nokia's plans, Facebook chat, Sony's tablets, Ofcom complaints, legal action and Charlie Sheen. We also look back at the 'cashback crisis' of 2007.

The British Retail Consortium and Google have launched a joint 'Online Retail Monitor' to provide insights into online shopping trends.

It reveals that the total volume of online retail-related searches in the UK grew by 29% in the first quarter of 2011 compared with the same quarter a year earlier. However, mobile retail search traffic rose by 181% over the same period. Overall, 11% of total retail searches in the first quarter of 2011 were made on a mobile device.

Sony Corporation has announced plans to introduce two Android-powered tablet devices from this autumn.

Both devices just have codenames at the moment; the Sony Tablet S1 has a 9.4-inch display, while the Sony Tablet S2 has two folding 5.5-inch displays.