I’m a big fan of Oz Solomon’s Project Line Counter from here http://www.wndtabs.com/, however there isn’t a version for Visual Studio 2008. I’ve got a work around though 🙂
Install the version for Visual Studio 2005, which fortunately installs even if Visual Studio 2005 isn’t present, then copy the following to notepad, save it and rename it to a .reg file, then double click it to enter it into the registry. After that, start VS2008 and you will see it there.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Addins\LineCount]
"FriendlyName"="Project Line Counter"
"AboutBoxDetails"="Project Line Counter Addin — Build 2.21.2.1024
Copyright (c) 1999-2006 by Oz Solomon
http://www.wndtabs.com"
"AboutBoxIcon"="C:\\Program Files\\WndTabs.com\\LineCount\\1033\\LineCountResources.dll,1"
"CommandLineSafe"=dword:00000000
"CommandPreload"=dword:00000001
"Descrption"="Counts lines of code in your projects"
"LoadBehavior"=dword:00000001
"SatelliteDllName"="LineCountResources.dll"
"SatelliteDllPath"="C:\\Program Files\\WndTabs.com\\LineCount\\"
John Stewien's Road To Somewhere Else 
That\’s awesome… thanks. For those of us running XP64, change the registry location to "…SOFTWARE\\Wow6432Node\\Microsoft…" and change the two directory locations to "…\\\\Program Files (x86)\\\\", and it should be there the next time you run VS2008.Stats for my project: 1,075,981 lines = 755,551 only code (70%) + 127,478 only comments (11%) + 39,552 code with comments (3%) + 153,430 blank (14%). Fun times.