This site is something of a labour of love, a semi-creative outlet for someone who can't help himself from wanting to comment and review - whether anyone is reading or not. However, it certainly pales in comparison to the extraordinary site The Complete Review, which was founded in the internet's infancy and now contains critiques of more than 3,500 books, all written by the same man: Michael A. Orthofer, an Austrian emigre who grew up and still lives in New York.
As Karan Majahan observes in this article for the New Yorker, "Orthofer's project has the self-swallowing pattern of a Borges story: if you set out to read the world, how can you stop?" It's a Sisyphean task, but hugely admirable - not least for the fact that he takes an internationalist perspective, reading and reviewing (and thereby helping to popularise) books from around the world in translation rather than focusing narrowly on fiction produced in the English-speaking West.
(Thanks to Adam for the link.)