Making links in SharePoint list URL fields open in a new window

Open the schema file for the links list feature:

C:Program FilesCommon FilesMicrosoft Sharedweb server extensions12TEMPLATEFEATURESLinksListLinksschema.xml
There should be two instances of the following:
< Column Name="URL" HTMLEncode="TRUE" /><HTML>[ CDATA[">]]>HTML>

Replace them both with this:
< Column Name="URL" HTMLEncode="TRUE" /><HTML>[ CDATA[" target="_blank">]]>HTML>

Note: Replace “< " with "<" and "[ " with "["