There have been several new mobile devices coming out, and now HP has one as well. The HP 2133 Mini-Notebook is $499 with Linux. (As with all of these new category devices, the price is quite a bit higher with xp.)
As the prices come down a bit (I think $300 is the sweet spot for education), these devices might be a good solution for a one-to-one computing device, falling somewhere between a handheld and a laptop. I am particularly interested in how Web 2.0 applications runs on these and what other educational programs are available.
Stay tuned for more on these new devices and their use in the classroom.