I just tried out mwalt's (the poster 2 posts above me) HDWall and I love the effect if gives my Diamond. I had used a similar transparency modification on my old Touch and also loved the effect. I find it makes the screen look and feel larger, and more aesthetically appealing.
Good job mwalt, and I hope you continue with it's development, maybe landscape support in the future ect.
Here's an example, notice the top & bottem bars are now transparent, making the screen seem larger:
Anyone know where I can get a copy of this background image:
Or just tell me where to find that background image file (windows dir?), as I could rip it from my old touch.