SharePoint Log Reader is a small utility to open and filter the SharePoint 2007/2010 ULS log files typically found in 12hive\LOGS.Each file you open will be appended to the list, so you can get a consolidated view of multiple log files.Version 2.0:
- Completely restyled (it's a WPF app now)
- Improved performance
- Loading multiple files at once
- Loading files by dragging them to the data grid
- More filters available

The 'filters' tab gives a nice overview of the available (and selected) filters:
