A good comparison that I viewed a while back was produced by IGN: http://xbox360.ign.com/articles/617/617951p1.html
A developers perspective comparsion: http://www.hardcoreware.net/reviews/review-348-1.htm
Gamespot Graphics Comparsion: http://www.gamespot.com/features/6162742/index.html
Xbox 360 Architecture explained: http://www.cdrinfo.com/sections/news/Details.aspx?NewsId=14842
PS3 Architecture explained: http://www.blachford.info/computer/Cell/Cell0_v2.html
I am not too sure which one is better as IMO they both have shown to be farily equal. However, it is my understanding that the Xbox 360 is cheaper and easier to developer as stated by industry experts and developers. (I am not going to go hunting for links but I have read it several times.)
All and all with the consoles being so close, I think what matters at least for 3rd parties is how much it costs. I think the 360 for this reason has a edge when it comes to support and is another reason why we are seeing so many "timed" exclusives.
Anyways, enjoy the links.