The IWL website coerces writers into giving it a go:
Check what famous writer you write like with this statistical analysis tool, which analyzes your word choice and writing style and compares them to those of the famous writers.
Any text in English will do: your latest blog post, journal entry, Reddit comment, chapter of your unfinished book, etc. For reliable results paste at least a few paragraphs (not tweets).
Here is the result from my post about Zumba:
Douglas Adams. An interesting result, considering that The Hitchhiker's Guide to the Galaxy and Dr Who really aren't my thing. I initially thought of Douglas Kennedy, having read A Special Relationship and State of the Union last year. (Actually, I would have been flattered to get this result.) However, I realised I'd got the wrong Douglas; obviously my lack of interest in science fiction isn't evident in my writing style. Other posts have yielded different results (I got Stephen King twice) - I could play this game all day!
Who do you write like?