This phase II trial aims to determine the safety and efficacy of erlotinib in patients with advanced pancreatic cancer who have previously been treated with up to one prior line of gemcitabine based chemotherapy for advanced disease. In addition, we will evaluate the feasibility and activity of dose escalation of erlotinib in patients who do not develop a rash. Clinical outcome will be correlated to EGFR status based on immunohistochemistry and gene amplification status as well as Kras mutations from archival tumor tissue.