Just spent the evening playing with PSK-31 using Digipan on my PC. I found some informative videos on K7AGE's youtube channel. The video below is just an introduction, there are more dealing with interfacing, setting up etc.
Inspired by it I got the Alinco DJ-X10 in USB mode and tuned into 14.070MHz and sure enough got loads of messages from amateurs with very little effort.
Obviously following on from the SSTV experiments I soon hooked up a couple of PMR446 handhelds and sent a few messages going across the ether!
Got a few wav files in the MP3 player so I will probably do some field trials tomorrow!