Very nice.
This script should make my life easier when working with log files from the shell. The important part is that it will make using certain commands with pipes much easier, like 'sort', 'uniq', 'cut' and 'grep'.
One nice addition would be the _option_ to build the regexp by analysing the httpd.conf file given the format name.
Another one would be to maybe eliminate the need to do the uncompression of the log file outside the script, with zcat or zgrep.