WEB Server Log File Analysis using awk/sed/grep

I'm trying to find a way to show large page sizes (page size in K) from multiple web server log files. Essentially I want to show only rows from a file where a specific column is larger than some value. Has anyone ever done this type of log analysis? If so, a snippet of code would be very helpful.

What does your log look like?

Its a series of space separated values. The header row is listed below:

time, IP, method, URL, Query, Status, Bytes Sent, Bytes Received, Request Time, Referrer