Damn, travertine tile gets real expensive when you buy enough for a kitchen/dining room, bathroom, and entry way all at the same time! I guess I know what I'm going to be doing for the next year.
The plan is to do the full bathroom floor and entry floor in the same way we did the half-bath - 2 rows of 2" tile around the perimeter and 8" turned 45 degrees on the inside. The same 8" tile will be run straight up the shower walls, with an accent row of the 2" tiles worked in somehow to keep it interesting. The kitchen & dining areas will be 12" tile run across the whole area, approx 200 square feet.
This is what I put in for the half bath, which convinced us to go with it in the other rooms (shown here before I painted the walls - not bad for my first attempt at travertine if I do say so myself!) :
Eventually (if we have money left over) we'll go with some granite tile for the counter tops in the kitchen and bathroom. Unless we save money somewhere along the line, plywood is more likely in our future!