how do I listen to WPL files

That's a Windows Media Player file. Microsoft dropped development of WMP for Mac long ago, but you may be able to use the free version of Flip4Mac. I know it works with Media Player's .wmv files. Work a try on the .wpl files.

It's here:

Windows Media player for Mac - Flip4Mac WMV Overview - Telestream

F4M simply does a conversion to allow the Media Player files to run in QuickTime, which s already on your Mac.

There are some Microsoft codecs that won't run on Mac at all. Such is MS....

If F4M doesn;t work, try Googling "wpl mac." Ther appear to be other convertor out there.

.wpl typically contain a link to a mediafile. What worked for me is opening the .wpl file with TextWrangler or something like that to find (and copy) the actual URL to the file location.

Most folks that send .wpl files are sending links off of their local machine. Get them to export mp3 or .wav files instead. (jm2c)