Here in the states, Sony's 13-inch VAIO Z series has been missing from the company's online store for months, but in Europe, at least, it lives on -- a quartet of Z21 series laptops have surfaced on various e-tailers as the possible successor to last year's Z11. So far, we're seeing a pair of configurations with a Core i5-2410M processor and 128GB of solid-state storage and two more with a Core i7-2620M CPU and 256GB in storage. Judging by this sample, ...