I think it would be cool if a developer tried a "build your condo," system on their website similar to those of car manufactures. For example, you could select the floor plan, then the floor level, then the colour palate, and options (hardwood versus carpet in bedrooms, parking spot, etc.).
If I was in the market I'd want it to go one step further. I'd want full customization of the cabinetry, appliances, etc...
I know there's a lot of problems with this but sometimes I find the options offered just aren't to my taste.