Apple's tablet will come in two sizes, one with a 10-in. display, cost as little as $600 in the US, and is the "best gadget ever made," an entrepreneur who said he's had the device for the last 10 days told his Twitter followers today.

Jason Calacanis, venture capitalist, chief executive of Mahalo.com, and founder of the Weblogs blog network, spilled the secrets to his 95,000 Twitter followers beginning late Tuesday.

"I've been beta testing the Apple tablet for the past two weeks and it's amazing," Calacanis said.

An hour later, he said he wasn't going to divulge and details, citing his NDA (non-disclosure agreement) with Apple, who had, he said, hand-delivered the tablet. "Note to press: No, not going to break my NDA w/Apple/steve so u can get jump on announcement."

Within three hours, however, Calacanis was doing just that.

Calacanis claimed that the tablet would come with three price tags of $599, $699 and $799 "depending on size and memory;" run a version of the iPhone OS. Unlike the smartphone, it would though allow multiple applications to run simultaneously; and connect to the Internet via both Wi-Fi hotspots and 3G data networks operated by AT&T and Verizon.

"There are two sizes," Calacanis said on Twitter a few minutes before noon Wednesday. "One is about double the size of an iPhone and one is 20% smaller than my Mac Book Air."

One of the few details Calacanis said he wouldn't disclose was the tablet's true name. "Can't show device or say actual name," he said on Twitter. Analysts, pundits and bloggers have put forward several possible monikers, ranging from iSlate to iPad, for the Apple device.

Calacanis' leaks will be confirmed or denied shortly. Calacanis, however, was adamant that he wasn't pulling anyone's leg. "I assure you I'm not joking and the specs are real," he said. "Most of all that this is best gadget ever made and NOT overhyped."