Ideas for subnetting w/N66U?

[BobMCT]

As I've been using this model router with Merlin firmware for several years now and like it, I have a requirement to split my LAN into two subnets. I realize each subnet requires a router interface and this model only has one.
Is there any way to redefine the subnets or any way to interconnect devices to accomplish this? Some device NIC's support virtual interfaces.
Any ideas/pointers/suggestions greatly appreciated. Thanks

 

[ColinTaylor]

Can you explain a bit more about why you need two subnets? Are there any access restrictions between devices on different subnets or the internet?

What devices are going to be connected to each subnet and how are they attached (number or wired vs. number of wireless).