Technically compatible with any portable device sized within the iPad's general footprint, Kensington's Reversible Sleeve ($10) has one major advantage over its competitors: it's cheap. The neoprene sleeve is black outside and gray inside, reversing if you prefer a gray exterior, with just enough physical space inside to hold the iPad when it stretches outwards. Though it might be dull from a design standpoint, the price is very hard to argue with…