I know exactly how you feel. My DS has hypotonia - specifically affecting his hands (and in his trunk leading to postural weakness). This is how writing tasks are for us too... add to that the worksheets really are boring - particularly for gifted and/or creative kids. Your DS and mine would get along great. LOL.
DeHe has really GREAT suggestions! I have started being a scribe for my DS on homework (particularly on nights where he has already had an hour of OT for writing)... He breezes through the work when I scribe for him (like he did like 5 or 6 pages of math homework so fast and happily when I was writing his answers for him and really the point of the work was the math not the writing).
Does you DS have hypotonia?
I found this story
http://teachingat.info/writing/index.html (and site) inspiring... I feel so alone - like, we know kids with asd and adhd/add and speech issues and all kinds of stuff but no one with a kid who has a high IQ with hypotonia... I find it isolating and demoralizing. And I have to KEEP EXPLAINING the nature of the disability over and over again to the teachers and school staff (nice people but sheesh). It's so hard when you got a smart kid with a very real and rather invisible disability.