I'm aware of four options:
1. a buckwheat pillow (is cheap, and looks cheap)
2. coastaletech armrest, $74.
3. the Wright custom armrest, >$150.
4. raise the existing console up higher $?
I have the Wright armrest, and though expensive, it looks like it came with the car, and is a quality item. The cover zips off for cleaning.
All these options (except #4) are described with pictures at http://groups.yahoo.com/group/toyota-pr ... r%20Prius/
for #2: http://www.coastaletech.com
for #3: Wright Upholstery Company, 1003 Douglas Street, Kalamazoo, Michigan 49001, phone (616) 345-7845
for #4, search the archives at the yahoogroups site. Not too far back in time.
In my opinion, this car must have an armrest! My right elbow is on mine constantly.