What's a good way to "standardize" the format of web content for importing into an app?

I'm working on a project where one of the requirements is to import articles from a website. The problem is that different websites have different formats. I could theoretically write some code that strips out extra content from known websites, but this is hardly maintainable. It sounds like there should be something already out there that can "RSS-ify" pages for me into some format, so that I can easily import content.

Is there such a service that I can just "plug" any website into? Also, what are my options here in regards to importing web content into an app, aside from this? How would you handle it?

开发者_开发知识库Edit: Two things that come to mind are FeedBurner and Apple's Safari browser, which adds an "RSS" button. (Safari Mobile actually does one better and renders a neat read view in iOS 5.) Are they relevant to this question in any way?

It seems that there is none. The best I can do is work with content providers to offer RSS feeds and such.