Early reviews suggest that Apple's iPhone will live up to its billing as the most anticipated consumer device in history.

The gadget is set to go on sale in the US on 29 June at 6pm local time. In one of the first public reviews of the device, Wall Street Journal columnist Walt Mossberg declared it "a breakthrough handheld computer". 

"Its software sets a new bar for the smartphone industry, and its clever finger-touch interface, which dispenses with a stylus and most buttons, works well," Mossberg said in an article co-authored with reporter Katherine Boehret.

Newsweek columnist Steven Levy likened the device to another famous Apple introduction, declaring that his iPhone experience was "fun in the same way as switching from an old command-line interface to the Mac GUI in the mid-1980s". 

Initial reviews of the iPhone were not, however, without criticism. While Mossberg declared the touch-screen keyboard a "non-issue", Levy and New York Times columnist David Pogue both said that the keyboard was slower than a smartphone keypad. 

All three reviewers also lamented the iPhone's Edge wireless data network. Mossberg classified performance as "pokey", and Levy likened the Edge data transfer speed to that of a dial-up connection. Pogue declared it "slow and horrible".

The reviewers also noted that the lack of Flash and Windows Media support can affect the web browsing experience, as it will leave sites that rely heavily on either technology all but useless.

Mossberg warned that the iPhone may not be right for average consumers who will not make frequent use of the web and email features, but concluded that it is "a whole new experience and a pleasure to use".

Levy declared that users who shell out the cash for an iPhone will get their money's worth "if only for the delight they get from dazzling their friends".

Pogue was likewise optimistic in his review, stating that "the iPhone is amazing. It's filled with incredible features, incredibly well done."

The iPhone will go on sale across the US on 29 June at 6pm local time.