Note that as of the date of this post, PDO_SQLITE will not interact with database files created with the current version of the SQLite console application, sqlite-3.3.6.
It is currently necessary to obtain version 3.2.8, available from http://www.sqlite.org/ but only by entering the URI manually, as there is no link. Go to http://www.sqlite.org/download.html and find the URI of the version you're looking for, then make the appropriate version number substitution.