Applied online, got an invitation via email to complete a homework assignment about a week later. Spent between two or three days on it. Fun problem, learned a couple of cool things while working. About 98% sure my solution was correct. But, received standard generic rejection letter a week after I submitted it, with assurance that they couldn't provide any sort of feedback.
I enjoyed doing the work, however I was very disappointed in the company's apathy towards it's applicants. Just a couple of sentences of feedback regarding how I can improve my code could have helped me tremendously in my job search. Just telling me that you're impressed with my background and experience, that you have decided to pursue other candidates, that you'll keep my resume on file (oh thanks), and that you are unable to provide specific assessment feedback to individual (as opposed to group?) candidates left me feeling like a sucker.