Dave,
Here's the link to Jeremiah Watt's Blog that has the stingray seat insert on one of his custom saddles. I think you (and the rest of us) will enjoy his carving, too. The guy does amazing work. I think you'll find a bunch of ideas that you may want to incorporate into your bike seats...heck, technically they're "saddles" too!
There are also examples of what he does on scrap pieces of leather to come up with different ideas for leaves, flowers, scrolls, etc., to use in his carving.
As an artisan, he's one of the standouts that always come to mind--he makes the Horseshoe Brand tool line, builds custom saddles (5-year backlog last I heard), does silver work, makes his own saddle trees--from raw lumber to rawhide-covered finished tree, and last Fall rode his bike from California to Norfolk, Virginia.
Beyond all that, I don't think he does much.
I post this here for the saddle seat inserts we were talking about, but I think everybody will find something to learn from...
Here's the link, y'all: http://www.westernfolklife.org/weblogs/artists/watt/