Agree with 905shmick. By just changing the subnet mask to 255.255.254.0 you would double your IP address capacity from 254 devices to 510 addresses. That should cover most people for quite some time in a home network environment.
While simple (dumb) switches do not take up IP addresses, Layer-2 (managed) switches do take up one address for their management portal. Wireless Access Points (WAPs) also take up one address.
It may have already been said that those that use more wireless devices, should manage their router's DHCP services a little more stringently. Ensure that you have locked down your wireless security, and use MAC filtering to ensure that neighbours aren't "piggy-backing" onto your network.