We've added 2008 household counts to the zip code display page at:
To see these demographics, just key in a zip code, address or click on the map. The counts for 2008 households will be displayed in the sidebar where the area codes used to be. The area codes are still available, just click on the marker or the link in the sidebar to open the infowindow which will have the area code as well as the household counts for the 2000 Census.
These counts were derived by determining the blocks that lie in each zip code, calculating the change in population from the 2008 estimates from the Census by county, extrapolating the household counts for 2008 from that data and summing by block for each zip code.