A very good approach to getting twice daily posts in is to be able to work your way through some common themes, and to do this using some lists of places around the net you can pull ideas or research from.

I've found that starting out with a wiki page that reads essentially "List of good sources about x", and then walking my way down that list looking at ideas and inspiration and things to collect, generates a good way to do a weekly set of collected links on a given area.