The present invention provides a method for identifying inhibitors of protein kinases and/or protein phosphatases. Methods are also provided for inhibiting protein kinase and/or protein phosphatase activity. Specific non-peptide protein tyrosine kinase and/or protein phosphatase inhibitors are provided. The protein kinase or protein phosphatase inhibitors of the present invention may be used to treat a number of conditions in patients, including cancer, psoriasis, arthrosclerosis, immune system activity, Type II diabetes, and obesity.