I purchased one of the new Ham It Up HF converters for testing a couple of weeks ago. Basically the converter goes between your RTL2832U stick and your external antenna and converts HF signals to be received on the FM band of your RTL2832U stick. SDR Sharp or HDSDR can then demodulate the HF signals as AM, USB, LSB, and CW signals. I was very impressed how well this setup worked. I hate to say it, but with everything tweaked as best as I could get it, the Ham It Up / RTL2832U combo easily bested my commercial HF transceivers receiver at times even though the commercial transceiver has all the DSP bells and whistles. This setup probably does not do as well as a $800 commercial HF SDR receiver, but for a $75 receiver ($25 for the RTL2832U stick and $50 for the converter) it's pretty impressive. You get a nice 2MHz waterfall display so you can pretty easily monitor an entire band. I put together an article and video at Ham it Up HF Converter | Ham Radio Science
, if you would like to know more about this.