Joel,
Sorry you didn't study/check the boards too much before you synced. I've posted elsewhere multiple times my recommendations for uploading/programming.
You are right, if you have multiple numbers listed under someone's name it will only upload one number for that name (I've been told it uploads the first number you programmed in, not the first one on the list). Also, the Prius only displays 9 characters.
I had to manually put in all the numbers into my T-610 from scratch and had, fortunately, asked for suggestions before I even had the phone. That saved me the headaches, for the most part. I still have 4 listings of the same person's name and am not sure which number is which b/c the part that says "Bartley Toy Cell" or "Bartley Toy Home" only shows "Bartley T" for each listing. Most of the others I did a better job shortening enough to tell which is which. This can mean some creative name entry to be able to read them. It would, I agree, be nice to have a more sophisticated system, but it is what it is, and I can only assume it's a limitation of the Bluetooth along with the fact that there are so many possible phones that will be used--with each of those having names and numbers programmed uniquely.
--evan