The BeagleBoard is a sweet little single board computer from Texas Instruments, based on the OMAP 3530 processor. It features audio in and out, S-Video and DVI out, USB, RS-232, and an SD card (though surprisingly it lacks an Ethernet port or wifi onboard, so you must buy some extra parts if you want internet access).
It has solid community support and well documented instructions for building an image with OpenEmbedded. The best place to start is by downloading a prebuilt demo image. Begin by correctly formatting your SD card. Then download MLO, uImage, and u-boot.bin from this mirror and copy them into the first partition. There is an Angstrom demo image available for the 2nd partition of the SD card in the same mirror (remember to unzip that image as in the detailed instructions above).This gives you a functional BeagleBoard to play with.
I was able to build and run Bug Lab's normal phoneME based Java stack thanks to Marcin. With a little tweaking Concierge's console runs and many of the Bug's OSGi services are available (obviously none for hardware that is not present on the BeagleBoard). We have branches with this build in it. (svn://svn.buglabs.net/bug/branches/hrw/oe-stable-2009 is more cutting edge as of this writing does not build for me, but svn://svn.buglabs.net/bug/branches/bug-osgi-on-bb is build-able)
I then threw some packages with Cacao+OpenJDK onto the BeagleBoard for comparison to the BUG (which uses the Freescale i.MX31 cpu) using the Scimark2 benchmark. PhoneME is about the same on both platforms with a small edge towards the Beagle, and Cacao/OpenJDK is a bit faster on the BUG. For starting up Concierge phoneME is faster than Cacao/OpenJDK and the Beagle is a bit faster than the BUG.
There is a big disparity between phoneME and Cacao/OpenJDK - phoneME is 50 to 100 percent faster than Cacao/OpenJDK. I'd really like to have the full classpath of OpenJDK over phoneME, but right now the performance of phoneME is still too great to pass up.