I also have considered creating a book based on movies. I think this could be quite interesting if I reviewed films that are relevant to typesetting. For example, I could review the movie 'Orphan' to display my knowledge of orphans in type.
I also had a look at some websites that I browse regularly, for example The Daily Street. I think this would be really interesting to create a book for as I find the content really interesting, and it would also be helpful as I wouldn't have to create my own content, I could just typeset it in my book. I think this is the idea that I want to go forward with. I think I will create an annual book of the 10 most successful blogposts. As The Daily Street is based on The Daily News, I think it would be interesting to create my book in a similar style as the newspaper, however not stick to it too closely, for example I won't use as many columns, however I will consider using a similar stock to newspapers.