Make sure you fully understand the rules of being an IC. The number one rule is: The element of control. An IC has it. A service cannot tell you the hours and/or days you have to work, the pay rate, or anything else of that nature. The rules that apply to the service (which is an IC faction) also apply to you.
Here's a web site with the rules: http://www.irs.gov/businesses/small/article/0,,id=99921,00.html