I have an average network, usuall stuff, server2003, 6 switches, couple of printers, 200 computers on dhcp, exchange.
 
There is talk of 250 more computers!
What do i do? There isnt space on the ip range right?
 
Help!

If you only have a class C network, i.e. 254 available IP addresses (or a 255.255.255.0 or /24 subnet mask) then your only option left is to use PAT.  My suggestion would be to get a decent router that can handle a larger subnet and create a private addressing schema.  Here's an example:
 
Internal IP Address ranges:
 
Servers 10.0.3.1-10.0.3.62
Printers 10.0.3.65-10.0.3.126
Switches/Routers 10.0.3.129-10.0.3.254  
DHCP 10.0.0.129 - 10.0.2.254
 
Subnet mark of 255.255.252.0 for everything
 
This gives you room for 62 servers, 62 printers, 126 switches/routers and 638 computers on your network.
 
Use PAT for all your DHCP hosts and NAT for all your servers translating them to real IP addresses on a 1:1 basis.

Thanks so much for the reply.
 
Im new to this and a little lost, and confused.
How or where to i turn on PAT?
Where do i specify the DHCP ip range in server2003.
 
Im still learning, all help is really appreciated.
 
 

You will need to turn on PAT in your router.  Refer to the manual on how to do so.  PAT stands for Port Address Translation.  What it means is as your PC's request data from the internet they are assigned a port on your external IP.  Once the data requested is returned, the PAT device forwards that data back to the requesting internal PC.  This is a very simplistic way of explaining it but about the best I can come up with on short notice.  Also, DHCP is configured in the Adminsitrative tools section of 2003.  If you don't see it listed you probably havent installed that service.  
 
Good luck!!