Has anyone ported the SAM7X lwIP demo for GCC over to the IAR tools .. I would like to compare uIP  with lwIP but I am using the IAR toolchain Thanks Ken

Not aware of any such port, but check out Adam Dunkels site for some comparisons – one of his papers contains a comparison table I think. Basically lwIP is more featured and therefore RAM, ROM and processor hungry.  It has the more familiar socket interface. uIP takes tiny RAM and ROM.  It’s main disadvantage is that it can only have one outstanding message at any one time.  This will make it slow if you send lots of small packets (so just send large packets and you are fine!).  The interface is less familiar and the application has to handle retransmissions rather than the stack – but otherwise I really like uIP.  It is also easy to understand and follow which is a boon.