Before it shut down, the popular posts list at del.icio.us was one of my regular internet visits. In early 2009, I wrote some scripts to grab to grab the RSS feed every hour, and then collate those feeds daily into one digest page. I've included those scripts.
I've also included a CSV and SQL dump of the database, someone may find the data useful. The original RSS feed scrapes are included but zipped up (>600k files, close to 500mb).
Database/RSS contain content from Mid-February 2009 until closure of the original on Sept 24, 2011.