Well Batt. Timings depends on so many factors. Like how many processes are running at backend, LCD brightness, Wifi signal strength, any USB and so on.
I got My Tablet x61 on 09 July 2008. On the first use, the maximum batt timing I was getting on a full charge was like 3:20 mins. I was like what is this?
Now its My 10th cycle of the batt. Today was My final exam, which went for 3 hours. I came to class and stared working My brightness was on half n a +, wifi on and a outlook, OneNote, Yahoo and MSN Mesng.. My batt gave me 5:49 mins. I thought that it would be gud if I work on full brightness. So, I worked for three hours and still it was 37%. and the time came was like 1:50 min.currently My Tablet is running around 98 processes. and My specs are 1.8 GHz C2D, 3GB, 160 @ 72 RPM. and WinXPTablet 2005. Except all Standard.
If you want the best timings out of it then use it like a tablet, read something or take some notes, normal brightness on 4,5 bars, wifi =on and it will give you around 6:30 + mins. and can be stretched further.
you are using Vista on which processor? that will also matter a lot.
I'm satisfied with My batt. im sure that I may not reach up to 8 hours, butt its far better than My previous one, where I use to get less than 2 hours.
Happy Mobility 
NAB
