Two and a half is still kind of bad, but I'm glad my suggestions help a bit. Aero is one of those things I wish they never added to Windows. It's just kind of dumb. I'd inquire with Sony about that battery, and stick with the suggestions I just mentioned. With a battery replacement, it might be fine. Then you could look at a newer computer with Ivy Bridge, which as I mentioned should have better battery life during lighter computing. Quite a lot of it is related to the ability to turn off cpu cores under lighter loads. It's not that the max tdp came way down, but they are improving the overall power management at a hardware level.
I can sympathize with you as I can type quite fast, but I would never be able to keep up with a lecture taking notes by hand. My handwriting speed is terrible, and it preceded regular computer use. When I try to write quickly, my hand cramps up.
I called Sony. My mistake I actually bought it Aug '10 so the warranty expired this past Aug.
Anyways, they told me I should change the settings etc. and the standard battery costs $135 (2-4hrs) and the extended battery (4-6hrs) is $219. Hmmm..