@iab - Thanks for the suggestion! I ordered a similar pair to those you posted and they do have an effect. It is not the largest change but I can tell that blood is flowing a little better in my fingertips (I’m using one on a single hand right now in a chilly room and it really does not get in the way too much, at least with typing, and I can feel that the fingertips on the wearing hand are warmer). I’m not sure if they would prevent a Raynaud’s attack outright on their own if I was having one, but they are at least an incremental help and the system would not be too hard to add to a direct warmer. Going to try exploring a forearm sleeve like you mentioned–my teacher also suggested a similar idea about integrating clothing with the technology so as to avoid having the solution being a completely separate device. A hand covering/wrist band would also be able to add some circulation and support for the warmer parts like the battery. Some directions to explore … and I will have to research more into pumping devices that you mention.
@jcharlesoo - It’s getting to that time of year for the annual Christmas Story showing 
I’ve gotten some good findings from speaking with people who have it (not as many as I’d like, unfortunately), but also supplemented by a lot of posts online by people who struggle with Raynaud’s in an indoor setting:
http://s3images.coroflot.com/user_files/individual_files/original_365272_X2HcMgiPhthmM8pDQwzJmRyug.jpg
I’ve done a little testing on which parts of the hand to warm up, but would like to do more. My classmate suggested that I explore heating the palm and wrist directly, rather than the fingers, but it did not seem to work for me, probably because of the deep location of the arteries vs. returning blood vessels as mentioned.
Below are some of the earlier sketches, I’ll be posting some newer ones tomorrow. I can already feel some of these being a little too techie-looking for who I’m aiming at (now if I was trying to help Star Trek’s Borg…).
Some model-making:
Above: An idea for a folding warmer that can heat the entire length of the hand to fingertip, but folds to be out-of-the-way if needed (could stay folded with snaps, magnets, etc.), while still being able to warm the fingers if you make a fist. The green stuff is thermal silicone, doesn’t heat quickly enough to be the heating channel itself, but could work well with imbedded heated elements.
Ideas for a solid warmer that fits like a ring so that you can retain finger use. This is a foam model, and most people who wore it (myself included) felt that the solid ring part was constricting. Next step is a solid warmer with a flexible ring attachment.
Variations on the idea
Wrist and palm attachment