From Softpedia and Joejoe , you can download four new Microsoft official Vista screen saver ported to Windows XP. All these new screen saver look very modernized. But my favourite is bubble, because it doesn't change the desktop background when it's running.
BtN's tips : I'm really wonder why Softpedia and original author didn't pack installation instruction. Those of you who don't know what to do with downloaded file, extract it to C:WindowsSystem32. And you can choose that extract screen saver in Desktop-->> (Right Click) Properties --->>> Screen Saver Menu. But Settings will not be working, you need to edit registry as in the readme included with download. For most of us, no need to bother about changing the setting unless we really want to mess with registry.