They are a free online chat website that is very similar to Chatroulette, allowing you to communicate with others without the need to register (but still providing a safe environment through other means and features).
Omegle also includes the unique Spy Mode, which connects three people at random. They introduced video chat into its system in 2009, and more recently the website has added mobile capabilities, allowing people to chat from their iPhone and Android devices.
Users can also connect with Facebook which lets you to chat with people that have similar interests.
This is currently one of the best alternatives available. This is always a fun experience, and can generate some interesting and fun discussion on topics (most often current affairs).
This site has been live since 2008 as a text-based chat system. From here one stranger asks questions for the other two users to discuss. Fans of random video chat will feel at home on the website.
Omegle has long been one a very popular site.