Check out the current 4 part series in Classic Toy Trains Magazine. It's a 4 X 8 logging themed layout. Here's a link to a video of it running:
http://www.trains.com/ctt/default.aspx?c=a&id=1474
Here's some ideas from the Atlas 3 rail site.http://www.atlaso.com/O%203Rail%20NS%20web/index.htm
Of course not all are 4x8's.
EDIT-Ooops! I didn't see that Texas Zepher already posted that link.
I'd add two suggestions to the good ones already posted. It looke like you have some space in the right hand corner to add to the layout. If you are not ready to do this now place a spur so you can link to it in the future.
Second, my layout top is flat like yours but with foam on top of the plywood. If I had it to do over I'd use WS's foam system or use their idea of having different levels of foam to get away from the perfectly flat surface.
Just my 2cts.worth.
Good luck and keep posting pictures of your progress.
Bob
Don't Ever Give Up
Ok, I have lots of ideas. If the picture is what you currently have it looks like a simple figure-8 inside of an oval. Are the two totally separate? Is there only the one train or are multiple run at the same time? Is this a simple AC power supply or do you have Lionel's or MTS's control system?
What exactly do you think it is lacking?
Idea:
1. Put two turnouts on the figure-8 so the train can reverse itself.
2. Add a turnout on the outside loop for a stub end siding that fits into the narrow part of the figure-8.
3. Add two turnouts connecting the two loops together so the train can move from one to the other.
4. Add four turnouts and a crossing at one end connecting the two loops together so that a train can go from either loop to the other in either direction.
5. Totally remove the inside figure-8 and replace with lots of industries to switch cars in and out of.
6. Totally remove the inside figure-8 and add two passing sidings to make a single track mainline where two trains can meet and pass each other.
Some of these ideas are obviously mutually exclusive.I don't know how many of these would fit on a 4 x 8 but there are lots of good ideas. Note especially O-2, O-3, O-7.http://www.atlaso.com/O%203Rail%20NS%20web/index.htm
I need some different ideas on track layout. This is all i can come up with. Does anyone have any ideas for a 4X8 o scale layout.
http://i197.photobucket.com/albums/aa41/jat875/IMG00309.jpg