Anything more recent than August of 2010 can be found in audio form at this website:
Click on the sermon you wish to listen to (listed in boxes to the right) then click on "sermon player" above where the sermons are listed. Click play and enjoy!
Sermons from June 2009 to August 2010 are available in audio form at the following website:
http://gatewaynwa.christianarchives.org/
Just scroll to the bottom and you'll see various sermons from Bro. Tony and Bro. Kin. The sermons are dated to make it easier to find the sermon you wish to listen to. Simply click where it says "play the archive" and listen!