I scrape only the front page once every ~4hrs (minimum)
Nearlyfreespeech.net doesn't have cron yet, so I'm using onlinecronjobs.com. If you want to scrape it on demand just go to http://hnweekly.watdahel.com/index/scrape
It's not 100% accurate, but it's close. The reason I did the website is so I can catch up with the good stories that were submitted earlier during the week (I usually read during weekends).
Nearlyfreespeech.net doesn't have cron yet, so I'm using onlinecronjobs.com. If you want to scrape it on demand just go to http://hnweekly.watdahel.com/index/scrape