Integrate Beyond Compare in Visual Studio Team Foundation Server (TFS)

"Tools" -> "options" -> "source control" -> "visual studio team foundation server" -> "configure user tools"

Add:

Extension:	.*
Operation:	Compare
Compare:	C:\Program Files(x86)\Beyond Compare 2\BC2.exe
Arguments:	%1 %2 /title1=%6 /title2=%7

Add:

Extension:	.*
Operation:	Merge
Compare:	C:\Program Files(x86)\Beyond Compare 2\BC2.exe
Arguments:	%1 %2 %3 %4 /title1=%6 /title2=%7 /title3=%8 /title4=%9

For more info:

http://blogs.msdn.com/jmanning/articles/535573.aspx