Interview Street provides Challenges for Hackers for those that wish to land in their dream jobs such as Dropbox, Justin.tv, Disqus, Facebook, and other similar companies.
You simply sign in with either Facebook or Google and are the presented with a list of challenges with point values corresponding to their difficulty. Each challenge comes with a description, sample input/output, and instructions for submission. You are scored based on the number of test cases your program passes and aren’t penalized for the number of submissions.
You also have access to their leader board which shows the current top Hacker at solving 18 questions with 52 submissions.
Once you have finished at least five problems you are eligible to apply the company of your dreams. If you are looking for a job soon, then this is an excellent way to prepare yourself for tough interviews as well as getting noticed by companies through Interview Street.