eQSL.cc provides global electronic QSL card exchange for amateur radio operators and SWLs. Since 2005 I am using eQSL.cc
This website provides an easy way of swapping digital QSL-cards.
As an eQSL-member you can participate in the eAward program.
There are several eAwards available (e.g. eDX100, ePFX, eWAS).
To my surprise, recently the ePFX300-PSK Award has been introduced.
I have been using the PSK mode often past years since it is an easy and reliable modulation
method for shortwave signals. Apparantly I have exchanged eQSL-cards with radiostations with 342 different prefixes using PSK in the past years.
Another piece of coloured paper to decorate to my "wall of fame" :-)