Amazon Mechanical Turk - The online market place for work.
Zirtual - Virtual assistants for busy people.
SerpClix - SerpClix is a click exchange network used to send more real clicks to your Google SERP. You can click to earn money or buy clicks to rank higher on Google.
Prialto - Prialto employs expert virtual assistants that can efficiently assist you with challenging tasks.
Testable Minds - Testable Minds is the platform used by researchers from the world's leading universities to recruit participants for their psychological and behavioral experiments.
TimeEtc - Time Etc offers virtual assistants for entrepreneurs and professionals.