No Sure what you meant by hardware, if you're referring to the router/switch, than that will be hard, the first suggestion (VLAN) is great, however, you need good knowledge of networking..
I have configured this type of network hundreds of times on my previous work place (ISP), using a german router call FUNKWERK, which splits your network into two different sigment(e.g. corp, and guest), on both WLAN and LAN, it's just like you have two different routers with one adsl line.
If you can get one of them from ebay or somewhere, give me a shout and I will send you a sample config file, all what you need to do is upload it to your router and off we go.
You can also achieve same thing on cisco wireless router(not linksys), but they're pricy (for no reason).