There are numerous sites which offer employment, but if you are an independent contractor or want only a short term job, then try Elance, the online resource for freelance workers. Whether your field is web design, programming, sales, legal, engineering, administration, translation, or finance, you can check out the current postings and bid for a contract.
The job bidding process works a bit like Ebay, so the more qualifications you include (verification of your credentials, taking their standardized tests for English proficiency, etc.), the better your profile looks when you bid for a job. For jobs which require stages or time, there are safeguards in place for approvals and revisions so that both employers and freelancers get their needs met within a neutral framework. Money is held in escrow for both parties so if there are any disputes, mediation decides where the funds go based on performance and feedback. It's a bit like hiring from a temporary agency; the job goes to a chosen candidate, but the agency governs the payment to the candidate, so if either the employee or employer does not perform as specified, the agency grants the appropriate party the payments due.
Elance is also great for people who need work done from freelancer; say you want a new logo or someone to do your books while your regular bookkeeper is on maternity leave, Elance will allow you to select a candidate from the bidders without a long term commitment.
In this new economy, it is nice to have options for employment that are flexible and reliable at the same time.