Time slices and timestamp resolution

[no_hope]

I am trying to do some wireless network performace analysis using libpcap and I have to deal with software timestamps provided by libpcap and the network card driver (i.e. not the timestamps provided by the network card hardware). I found that software timestamps have effective resolution/accuracy of about 1 millisecond, though the values are given with sub-microsecond precison.

Is it possible to configure the kernel to get more accurate timestamps?
Is it possible to configure scheduler to use smaller time slices?
Could somebody suggest ways to configure the vanilla 2.6 kernel to be more "real-time"?

Thanks