The first device based on Google's open source Android mobile platform has launched today in a joint UK and US press launch.

The hotly anticipated phone combines the look and feel of the Apple iPhone with a full Qwerty keypad.

Dubbed the G1, the first Android phone was built by HTC and is a joint collaboration between Google and mobile operator T-Mobile.

The device will be available in the UK from November on a T-Mobile contract priced from £40 per month that will include unlimited web browsing.

The G1 has a touch screen and slide out Qwerty keypad, which should appeal to a broad range of users. T-Mobile and Google said that the phone is ideal for all mobile communication purposes, whether calling, texting, email or instant messaging.

Users will also be able to download third-party applications from the Android Market in a similar way to Apple's App Store.

Core Google tools such as Maps, YouTube and Gmail are built in. Gmail users will be able to use the device to synchronise their email and calendar, while most other POP3 and IMAP email services are supported. There is also 3G and Wi-Fi support.

Early reactions from industry experts have been mixed. "Google Android will be addressing a very similar market to Apple with its iPhone, i.e. early adopter, wealthy, high tech users," said Carsten Brinkschulte, chief executive at email platform provider Synchronica.

"Therefore, it is unlikely that we will see Gphones in the emerging or mass markets any time soon. My prediction is that the Gphone will have very little impact on the mass market, where feature phones dominate."

Abid Warsi, of web design firm Webcredible, said: "Given that Google doesn't make the handset itself, and the software is being given away free, the Android operating system will be funded by advertising, and the jury is still out on whether consumers respond particularly well to mobile phone advertising."

However, Warsi conceded that, as Google revolutionised web advertising on computers, it has the potential to achieve the same success with mobile advertising.

"One area where this phone running Google's software should certainly excel is in the usability of its text input method," he said.

"Touch-screen functionality has proved an issue for many aside from the iPhone, but this phone offers a keyboard in tandem with the touch screen to give the consumer a choice."