If you're on Windows, you owe it to yourself to check out a little known Microsoft utility called logparser: http://mlichtenberg.wordpress.com/2011/02/03/log-parser-rock... It effectively lets you query a CSV (or many other log file formats/sources) with a SQL-like language. Very useful tool that I wish was available on Linux systems.
LogParser is one of the few things I really miss from windows. I think there are unix equivalents, but I haven't had the time to invest in learning them. Pretty much every example in this article boiled down to 'Take this CSV and run a simple SQL query on it'. Yes you can do that by piping through various unix utilities or you could just use a tool mean specifically for the task. I'd like to see the article explore some more advanced cases, like rolling up a column. I actually had to do this yesterday and ended up opening my data in open office and using a pivot table.
