I have personally used Elance for several jobs. You can get some kinds of things done pretty cheaply - but beware - you often get what you pay for. It is tempting to grab at that really low bid. But you will often be unsatisfied with the results. Be careful. Use highly recommended contractors. Expect to pay a fair price. It can be very convenient. I really love the concept. One quick tip: Be as specific as you possibly when you post a job. I mean VERY specific. Vague job posts will cause headaches. It wastes your time and is unfair to contractors also. Best wishes!
I have written some advice on this subject: