uxn for the nokia n900. very work-in-progress, it can run the amiga demo. no touchscreen or keyboard input yet.
copy your chosen rom and the uxnemu.uimage to the first partition of an sd card (fat formatted). you must rename uxnemu.uimage to uImage. boot the device and run the following u-boot commands:
fatload mmc 0 0x801f0000 <your rom> run trymmcboot