Apple has released details of its upcoming hardware and software releases at the World Wide Developer Conference in San Francisco.

The company unveiled a series of new products, including an upgraded iPhone handset, new MacBooks and an updated Safari web browser.

The 13in and 15in MacBook Pro notebooks will sport the same battery and processor improvements introduced earlier this year with the 17in version, and Apple is promising a battery life of up to seven hours. The revised MacBook Air portfolio will see new processors and a price cut.

Perhaps most importantly, Apple unveiled the new iPhone 3GS handset which, as previously rumoured, will sport double the memory of previous models and a faster processor with the ability to capture video.

The new 32GB and 16GB models will keep the current prices of $299 and $199 (£185 and £123), while an 8GB model will remain on the market at $99 (£61).

The iPhone 3GS will be released in the US on 19 June, two days after the iPhone 3.0 software update goes live. Details of a UK release were not given, but the company said that the model would be rolled out internationally "in the coming weeks".

Company executives began the keynote by announcing the official released of Safari 4. The browser has been available as a beta since February, and features a faster JavaScript engine and the ability to run as a native 64-bit application under the new OS X Snow Leopard release.

Apple also confirmed that Snow Leopard will arrive in September. The operating system will be the first OS X build to be offered exclusively for Intel-based Macs.

The company said that the update will cost just $29 (£18) for users of the current 10.5 Leopard OS X build. Users running the older 'Tiger' software will have to pay $169 (£105) for the update.