Pen Again ergonomic pen.
I had one of these new pen bought for me, as using normal, thin biro's and pens aint so easy for me anymore. The pen is great, comfortable to write with and easy to write with despite my numb, pins and needles fingers.
The is a (U.S) website:
A google search will show you where you can get them locally (I am in Melbourne, Australia)
The Pen Again has been a great help to me, so I figured there would be other MS'ers who will find it just as useful