Recently, I had cause to dig into my server logs for a detailed analysis of Googlebot activity. Urchin stats doesn't let me see exactly when it "comes", what pages it "visits" and what result occurred. So, I had to download the server log for the month of February to see the activity during the last few days (it was a 16MB file uncompressed). Working with such a large file in Wordpad is awkward because it does not load the full file all at once. You have to keep scrolling down and scrolling down as it pages through the file. Excel didn't help either because it has a limit of ~64,000 records/lines that it will load. So, I built a quick, no frills utility to chop up large text files into smaller, more manageable text files. I figure it might be useful to some of you too, so I've packaged it up as freeware. http://www.seo-help.com/html-tools/file-splitter.html
Might not help you, but for me, this is what I do... If your logs are on a *nix serer (and you have shell access), or you are running Mac OS X (BSD at it's core), you can use grep to quickly do it. I can spin through gigs of logs in seconds. For example: grep Googlebot [your log file name] Code (markup): Will spit out just lines containing "Googlebot".
Yea, I just have a lowly hosting account. In my recent, specific case, the logs for February were already archived and I had to uncompress it before I could dig into it. It's just as well that I did it manually - I noticed a few unrelated things that I needed to address.