The Kneeslider is a great site. filled with all kinds of wonder stuff about motorcycles. Here's another picture and link to an article about radial engined motorcycles. I agree with Jeff, these engines are beautiful.
If you write Biker Poetry or Stories, consider submitting your work for publication at Songs of the Open Road, Uglicoyote's new Biker Poetry and Writing eZine/Blog. For more info, or to submit your work, just click here.
If you have a biker/motorcycle related site that you would like to add to this constantly growing list just e-mail Uglicoyote. Commercial sites are okay as long as you offer something for bikers other than just stuff for sale. Reciprocity (link-back) is the right thing to do and will help you build karma. Some of you need the help.