Today, 2-in-1 detachable designs are all the rage in PCs as Intel and its partners attempt to deliver the best of both worlds. But way back in 2002, HP was one of the first to offer a convertible tablet design in the Tablet PC TC1000. For a fairly steep $tk, this 10.4-inch device featured an innovative swivel design, digital pen and a keyboard dock. The slate portion of the TC1000 weighed 3 lbs., and the combo weighed 4 lbs. While the Transmeta processor was sluggish, HP would later follow up with a zippier Pentium M chip. What was missing was an OS optimized for tablet use. The touch-friendly Windows 8 software is much better at juggling work and play than Windows XP Tablet PC Edition.