[komlenic]

For what you're looking to do, once a day is plenty often enough. (How much does karma change in a day and does it matter if your site is a few points behind?)

If it were me, I'd cache the results of an api call to HN with a last-retrieved timestamp and check against that for requests > 24 hours to retrieve again.

[robeastham]

Agreed. I guess it doesn't really matter if my site is a few points behind. Timestamp strategy makes sense too. Thanks!

I like the look of http://api.ihackernews.com/ and so will poll this rather than scrape - thanks for the tip hardik988 and for all the other comments too.