My boyfriend has been on Tarceva since December 2006 (so over 1 1/2 years). He takes 150 mg/day. He did not lose any hair. He developed sores (like really bad, deep pimples) on his shins and forearms about a year into his treatment. It is extraordinarily important to keep the sores clean and drained. Once he let them go and they got real deep. A month long anti-biodic treatment worked to heal them up. But be careful not to touch your eyes as he did get several eye infections until he learned how to manage the sores.
What he found was that the sores travelled along his hair follicle, something the doctor's didn't figure out. So he started plucking his hair around / in the sores. This has helped and the sores are so small now, he can wear shorts and short sleeves and not feel like "a very sick person/leper."
His Stage IV Metastatic lung cancer is gone. Well, that's what the onoclogist believes. He has had no reoccurance of the cancer and he is able to do all the biking, walking, and sailing he wants to.
So that's our experience! Wish you well. All I know is that Tarceva is a miracle drug and worth every penny.