Thank you all for your helpful advice and suggestions. I requested and received a $25 voucher. I agree that arriving safely is most important, but as I learned from a fellow passenger and from this board, this particular flight experiences in inordinant number of mechinical cancellations. My delay was actually closer to four hours. Most frustrating was that I couldn't get on as a standby on three other UA LAX-SFO flights, missed my mid-morning mornings. Thanks again.