What's the good way to get messages from a specific facebook wall?

There is a groupwall of which i wanna download and store all messages in a db. In the documentation I cannot find a good way to do it. Did I miss something? What's the good way to do this?

From stackoverflow

• I'd be really surprised if they weren't available as an rss or atom feed for downloading. (It's not using the API, but is probably the cheapest way.)

  Zoltan Lengyel : Probably there is an rss for that, but i couln't find any. At least not one with the messages. There is one with "you got a wall message" though.

  Ali A : That you got a wall message should be a feed of all wall messages. Have a look at it.

  Zoltan Lengyel : groups don't have the you got a wall message stuff either, a really can't find feed for the group wall :/