Staples carries a number of decent-looking glass desks (a whole lot better than the garbage wood desks they stock).
I went with the Z-Line Galaxy desk for my G5. They had several other glass desks, but that one seemed to have the best balance of size, price, and stability. Best feature is that is has a nice, thick rim around the edge that ISN'T glass--it's smooth, rounded plastic of some sort. This is much less cold when you lean on it, and it keeps you from chipping up the glass or hurting yourself if you bump it.
It comes with a monitor stand, but I just didn't put it on mine, since the Cinema Display takes up essentially zero desk space anyway, and it would have been too high up with that stand regardless. My sole complaint about it is that the keyboard tray isn't quite wide enough to accomodate my mousepad and older Apple keyboard. I think were I to be using the newer, "borderless" keyboard that came with my G5 and a mousepad that was rectangular instead of oval, it'd be ok.
It's $150 now, but I got it on sale for $100. Also, one other advantage of Staples is that for like $20 you can get their furniture coverage plan, which includes accidental damage and even wear-and-tear, so if you're a stickler for appearance and scratch up the glass, or you break it, they'll replace it.
This link should work:
http://www.staples.com/webapp/wcs/s...0051&langId=-1&productId=121072&cmArea=SEARCH
(Side note: I actually wanted to get a nice locally-made, or at least US-made wood desk, but they simply do not make wood desks in the size I want that will accomodate the G5 case. I looked EVERYWHERE.)