I just got back into Ham Radio last Oct 2010. My new callsign is KJ4YQK. I started out with a low power HF radio called the Flex 1500. I like the 1500 so much I pick up the 5000a model. Both radios are software defined radios.
Software Defined Radios (SDR) are radios that consist of hardware and software. This architecture allows dynamic filters and digital processing of intermediate and audio frequency. This enables a operator to filter out noise and interference on a signal. http://www.flexradio.com/About.aspx?topic=whatissdr.
Here is a image of my HF radio software: