This article by Waldek Mastykarz describes how you could achieve that with Content Query Web Part. It's seems to be perfect for your scenario.

This article by Waldek Mastykarz describes how you could achieve that with Content Query Web Part. It's seems to be perfect for your scenario.

In case you do not want to use Content Query Web Part, the alternative is to use Data View Web Part, check how you can Add a linked data source and Display data from multiple datasources.