This rocks! written and tested by the best office developers, will help you troubleshoot your 2007 and 2010 farms!
ULSViewer allows users to open a ULS log file and display its contents in a user friendly format. Users can then perform advanced functions such as filtering, sorting, highlighting, loading logs, appending logs, etc in order to single out the data that is important to the user. This information can be used to diagnose problems with machines running ULS services, or to monitor machines and the events they create in realtime.
reposted from Christophe’s blog