Useful tool of the day, MergeLog:
mergelog is a small and fast C program which merges by date httpd log files in 'Common Log Format' from web servers behind round-robin DNS. It has been designed to easily manage huge log files from highly stressed servers. mergelog is distributed with zmergelog which supports gzipped log files
This solves my problem where due to load-balanced webservers my logs are split over multiple machines. It also works with the combined log format too.