The song is called "A minor incident" by Badly Drawn boy.
It was a fantastic drama, I cried at the end! I haven't read the book but I looked it up this morning and the reviews for it aren't great so I shan't be putting it at the top of my to-buy list!
I was so impressed with Tom Hardy (played Stuart) though, thought he was fantastic. It really made me think differently.
Natalie, stuff the reviews and borrow a copy from your library. It's a very moving, sometimes funny (remember 'boing boing whoosh'?) and very well-written book. The illustrations in it are Stuart's own, animated for the purposes of the drama, and it has photos of him as well.
It's a different type of biography, but no less rewarding to read.
I googled this title and am intrigued. I hope this airs in theUS. I will look for the book ASAP. There is a US edition of the book out so hopefully I will be able to obtain it without too much trouble.