Anybody using this program with a sdr dongle?

Yes. And GCW uses it too.

I can't seem to get gqrx to see my R820T SDR. Any thoughts?

do a lsusb and let's see what it says

You need to blacklist the rtl module. I think it is  dvb_usb_rtl28xxu (at least that is the one that has always gotten me) if you start gqrx from a terminal it tells you what module has claim to it.

Try the command
sudo rmmod <module>
As a temporary fix and then start gqrx

Thanks guys, I did get it up and running real early this morning.  I did have to blacklist the dongle, but also added rtl-sdr, and GNUradio.  Not really sure if I needed to add the extra software.  I also have bumped up the Kernels over the last couple weeks and maybe should have left that alone.

There is no magic in running these on Linux compared to Windows you still need plenty of processing power.  My old laptop processor is quite overwhelmed running a USB SDR.
At least I was able to pull signals from my scanner discone antenna with the rat-tail adapter.

You pretty much hit the nail on the head. Theres some amount of work in getting it setup and it still takes the same amount of CPU power.

Guess I've been lucky then, I found it a lot easier to get one running under linux than windows, have even run them on a live disk.

I have two different SDR receivers, under linux I can use either one.  One the windows computer, I have to use the one specific receiver and it must be plugged in to the one specific USB port.