2011-04-01 Some searching (and some more searching) ...
Some searching (and some more searching) seems to suggest that there is no current offering in dab / dab+ receivers in the form of an usb stick with linux drivers. Google searches only find one project which talks about hardware which is very specialized or not available anymore.
The weird thing is, ubuntu comes with a dabusb.ko:filename: /lib/modules/2.6.32-30-generic/kernel/drivers/media/video/dabusb.ko license: GPL description: DAB-USB Interface Driver for Linux (c)1999 author: Deti Fliegl, deti .at. fliegl.de srcversion: 42A420F0B848548BB5209BB alias: usb:v0547p9999d*dc*dsc*dp*ic*isc*ip* depends: vermagic: 2.6.32-30-generic SMP mod_unload modversions 586 parm: buffers:Number of buffers (default=256) (int)But I can only find a dab reference reciever as a project Digital Audio Broadcasting by (indeed) Deti Fliegl, which references a hardware design by BayCom for an usb dab receiver by BayCom which looks like it now should live at Terratec. It does link to pages about the Terratec DRBox1 on their ftp server but I can't find it on the Terratec products website anymore. For as far as I can see this device does not support DAB+. But it does allow full access to all intimate details of DAB. A public version of this can be seen at www.dabmon.de.
The inspiration for this search was the news that commercial radio stations in the Netherlands will start testing with DAB+ somewhere in the future. There is a DAB feed for the public broadcasters already. If this gets accessible on a budget I will be interested.