Twilio - Brings voice and messaging to your web and mobile applications.
Micro Work 4 all - New Website aiming to get more workers and job seekers to perform tiny task and make money.
Plivo - Plivo simplifies your customer engagement.
Picoworkers - Earn money from doing short, easy tasks similar to Microworkers. Picoworkers is the best alternative to Microworkers I ever find.
MessageBird - Reach 7 billion phones in seconds via SMS, Chat & Voice. Try it for free and improve your communication.
Amazon Mechanical Turk - The online market place for work.