There are some standard log file formats out there. Here's something on W3C:
http://www.w3.org/TR/WD-logfile Google on "log file format" for more.
A group in my company is floating a standard that allows errors to be forwarded to a central monitor. Log4J and similar tools often have pluggable formatters, so you can change formats by simple configuration options.
Was that the kind of thing you were interested in?