I'd get a tablet, but if you are in the mood to tinker then you might want to look at the latest kit from Tin Can Tools. They just listed a new kit that includes a 10" Pixel Qi screen. It's definitely not something the average computer user would want, but if you've already gotten into the DIY world then this could be appealing.
The kit includes the Pixel Qi screen, cables, an adapter board, and an Animal mini board. That's most of what you'll need to use the Pixel Qi screen with any number of DIY kits like the BeagleBoard or the PandaBoard. It lacks a power supply, though that might be because the Pixel Qi screen has a low power mode and thus doesn't really need it.
On the other hand, I'm sure most DIY enthusiasts would have a spare laying around.
It also lacks a touchscreen component, which was probably a good idea. That alone would like add another$100 to the price; the PixelQi screen needs to have the touchscreen mounted in a particular way so that it doesn't impair the screen's ability to function outside.
This is a rather expensive kit, of you ask me. Other than curiosity I'm not sure what value it offers over that of a regular LCD screen to make it worth the extra $100.