I was evidently feeling really good today. After all of my previous attempts met with not making it to the top, I met a friend at his place and we decided to try Old La Honda again. We made it up in 31:30 and then continued up Skyline to Kings before heading back down.
More interesting, I found for the first time that I can ride continually (at least fast enough to not fall off) on a 7% grade without my heart rate leaving the aerobic zone.
So how far do I still have to improve?