Last night,i attended a Techno savvy evening and one of the hottest topic discussed was some of the devices that could challenge Apple’s dominance of the tablet computing market. It may have unceremoniously canned Project Courier, but Microsoft has made no secret of its desire to go head-to-head with Apple’s iPad in the tablet space. Steve Ballmer, Microsoft’s chief executive, said developing its own ‘slate’ was one of Microsoft’s top priorities, and the hardware division has been using its Twitter account to post pictures of a forthcoming product, which some have speculated could be a tablet computer. It’s surely only a matter of time before Microsoft unleashes its iPad killer on the world. Whether it can truly challenge Apple’s device remains to be seen .Research in Motion, the company behind the BlackBerry, is working on a tablet computer of its own, according to industry insiders. It will go on sale just before Christmas, and will cost roughly the same as Apple’s device. The "BlackPad" will apparently feature Wi-Fi, but not integrated 3G access – users will instead need to piggyback on their BlackBerrys to get online over the mobile phone network. But the big question, of course, will be whether or not it has a keyboard – BlackBerrys are famed for their Qwerty keyboards, and RIM’s previous attempts to do touch-screen only devices (original Storm, anyone?), were criticised by many users. Perhaps the Canadian company will opt for something like its new Torch – a touch-screen device with a slide-out keyboard?Robert Fraser a developer from Canberra mailed me yesterday bragging with how he have had a sneak preview of Samsung Galaxy S that could come the Galaxy Tab, a tablet-style computer from the Korean manufacturer that runs the Google Android operating system. Samsung is expected to reveal more details about the Tab at a special event on August 11 where Robert will be attending, and insiders say it takes many of its design cues and key features from the Galaxy S. Given Samsung’s computing pedigree, the Tab could turn out to be a real gem.Dell’s Android-based tablet is little bigger than a smartphone, but is designed for mobile data consumption rather than making calls on the move. It runs Android 2.2 and supports Adobe Flash, and thanks to its Snapdragon processor, is surprisingly fast. But it’s hard to see who this gadget is aimed at – it doesn’t offer the same sort of satisfying and immersive experience as a large-screen tablet, such as the iPad, but nor is it as capable and compact as a smartphone.I have been using one for the past few days courtesy of Dell employee who shipped for me a sample.