Just for a laugh, I though that I'd try running RadarBox on my new Asus eeePC 901 Ultra-portable laptop. It's not really built for this sort of application and is sold as a "Netbook" to allow easy email and web access when out and about.
The spec is:
Windows XP SP3
Intel Atom CPU N270 @ 1.60 GHz
1.33 GHz 0.99 Gb RAM
8.9 inch LCD display
12 Gb of solid state storage, split into 2 drives of 4 Gb and 8 Gb
A very cheap and nasty 2 Gb SD card in internal slot to boost storage space - no HD fitted
And the result is - RadarBox runs :-)
I installed RB on the SD card to save the internal storage of the eeePC. The limitation of the small screen is the main drawback and RB does run slower than on my normal laptop, but the CPU loading is between 25-46% with the refresh rate set to 4000 (about once every 4 seconds). Live aircraft only, not accessing Network data and sharing deselected as I didn't have the eeePC connected to the Internet for the test. I wouldn't really recommend running this setup as a practical RB unit, mainly due to the screen size, but it goes to show that you don't need a supercomputer to run RB 2009.
Pictures to follow as I'm not clever enough to figure out how to Bluetooth them from my mobile phone to the eeePC!