Project Inkwell's Spark is not only a potential OLPC competitor because of its handheld, UMPC form factor and K-12 educational focus, but also because it doesn't look like it's made exclusively for the preschool user base. The Spark was developed in conjunction with the design firm Ideo, and though details are vague, the visuals are somewhat revealing. The Spark looks roughly the size of a PSP, with a +/- rocker switch and scroll wheel adorning the left and right sides of the handheld.
There's no mention of touchscreen functionality, but the screen looks to be lined with buttons and comes with a case housing a foldout keyboard, plus room for a mouse and spare battery. Less visible features would include Bluetooth and Wi-Fi. It's still too early to talk release or pricing details, but this seems like a concept that's very feasible to produce. [Tuvie via Coolest Gadgets]