I spent a lot of time searching and reviewing sites before, and especially after, my initial post to this thread. While I can understand Myspace's popularity due to ease of use and other reasons, it's just not for me. Of the sites mentioned above, I checked out Soundclick and Garageband, plus many, many, many others. I did not run across Libsyn or Digitalmusician; so I haven't seen them. The one site I really did like, and may do something with if I ever actually record something that sounds decent, is
Bandcamp.
I read practically everything on the site about how it works, and it seems to make sense for what I want to do. I also looked at various sites that various bands had set up using the Bandcamp platform, and what they were doing seems to suggest that it works well.
It's a relatively young site, around a year if I recall. One thing I noticed in my research was that a lot of music hosting sites have been started and have since disappeared, which is a consideration.
Another aspect of being young is that a lot of their plans haven't been implemented yet. They wanted to start by focusing on the music first, the uploading, playing, and downloading; and I really like how that is set up. They haven't yet done things like being able to post your tour dates.
So based on what I've seen, I think some of you may find it worth checking out.