lilina:

lilina is a simple but powerful news aggregator written in PHP. No database is needed, RSS/ATOM parsing is done by the excelent MagpieRSS library (it is included, no additional installation needed). It features feed auto-discovery and an easy-to-use interface.

Installation is quite simple, just untar and edit conf.php. Make sure that cache/ and .myfeeds.data is writeble by your webserver.

不知道不需要数据库还算不算优点，但这个lilina确实非常简单易用，很容易稍加修改个人化。缺省的界面也很简洁漂亮。特别的，通过javascript和cookie，完成了类似书签的功能。

我用它做了个网页，聚合flickr上我感兴趣的tag下的图片。