Thanks for the suggestions--
I was fitted to the bike when I first got it, mid April. It's probably time for a double check on the fit. The pain is localized to the top of the muscle, just below the elbow. No problems with hand/fingers, so I don't think it's carpal tunnel. Other activities are the same. Really the only difference this summer is the kind of bike I'm riding. I've done the same work, ridden approximately the same number of hours in the past few summers. It's entirely possible that I injured myself lifting or carrying something--but nothing I remember. I *do* work with my hands a lot, but have never had this kind of pain before. One thing that occurs to me is that the Bianchi is so light that I tend to pick it up with just my right hand when going up stair or through doors sometimes (like when I ride to work). That could be contributing.
Knotted--I was just guessing about the palmarus longus, based on pain location and the picture in my anatomy text. How did you know that you didn't have one? Unless of course they told you back on your planet before you made the jump into lightspeed to come over here..."...the only way they can tell we're not human is if they detect the lack of a palmarus longus..."
I'll look for a tennis elbow strap at the drugstore. I'll also go back into LBS and ask them to look at the fit again. I'll let you know if I figure anything out! L.