There are scripts out there who do this for you, you can just host these scripts on your server and include a bit of code in your website. These scripts are called aggregators, i don't know any by name, but i think if you use google a few will popup.
I added a manual feed to my websites, but how difficult is it to make it automated? Everytime I write a news article I'm having it add it manually to the feed which is time consuming, so I want it to be automated. I ask you because I know how capable you are from your work on thumblogger.
From this evening on every blog on thumblogger also has it's own aggregator (what is a aggregator?)