Turn log4j or similar logfiles into a Python list object
Called from command line, this python program counts the lines in your logfile with ERROR, INFO, WARN etc.
You can also import the function generate_log_report from it and use the returned list object in your Python program for further processing.
A Ruby file parser/interpreter/preprocessor that comments lines of code based on conditions at the time the file is required. Very handy to implement debugging logs and code that has to be commented (not just dynamically switched off).
Java exception extractor. This utility will parse all files (either plain text or bzipped) and tries to search for various exceptions. It then tries to match exceptions against grouping rules (regexps). It is also able to group unrecognised exceptions.
Use python to parse privoxy log in clf format and refer to wot ratings of the site and then dump the data in a sqlite database for statistics generation later.