I did a quick archive search and hadn’t seen this mentioned before - it
looks like someone is making a 2-chip RF → USB2.0 front-end that would
be a great fit for GNU Radio receive-only applications:
http://www.mirics.com/tinymce/jscripts/tiny_mce/plugins/filemanager/files/Mirics_MSi3101.pdf
No idea how ‘real’ this is, but it looks like fun.
Eric B.