The go-to tool for trapsing through SharePoint's ULS logs has always been ULS Viewer, attributed to Daniel Winter (Blog | Twitter) at Microsoft. However, obtaining this tool has recently become a problem because http://code.msdn.microsoft.com/ULSViewer no longer brings you to a place you can download it.
Apparently Microsoft has retired the MSDN Archive Gallery which hosted this tool.
I am glad, in this case, that I am slightly OCD and save all of my downoadable installers in an organized manner and back them up. Thus, I can make avaiable the latest copy of ULS Viewer that was available (version 2.0.3530.27850 10/09/2009), as far as I know. According to the license that accompanied the download and applied to the MSDN Archive Gallery, this is legal for me to distribute here. These are the original unaltered files with modification dates from 2012 when I downloaded them.
ULS Viewer
The ZIP archive contains the two original files--a Word document describing the tool, and the executable file.
A good overview of the tool is avaiable in this article or this blog post. There are, of course, other log viewer tools for SharePoint that are out there. I encourage you to try them out to see which one works best for you.
Please direct any questions regarding the retirement of the MSDN Archive Gallery to [email protected].