A friend of mine is looking at buying a high end MP3 player for music and video.  This would mostly be used in his car, running the device through the Aux In in his factory deck.  He was looking at the Archos 504 w/ 160GB hard drive.  That retails for about 600 dollars.
 
I was wondering if there was something with similar storage in a portable PC flavor?  Does such a product exist?  It would be really nice to have something that would play MP3s and video, while also including WiFi and web capability, an email client and MSM.  The big thing is storage.  I can find all sorts of PDAs with flash memory, and ever a few with ~4GB hard drives, but nothing with large storage capacities.  Any help would be appreciated.
 
Edit:  Forgot to mention, a touch screen would be very nice.