OpalStaff Makes the 2011 Inc. 500|5000 with a Three-Year Sales Growth of 107 Percent Millersville, MD, Aug. 31, 2011 (GLOBE NEWSWIRE) -- OpalStaff, a leading technology-based staffing firm, today announced that its 3-year growth of 107 percent earned it the No. 2,275 position on the...