Most distros will allow you to set up two nics.
Some nics can be set up to act an a WAP, which can be handy. Ubuntu and CentOS from your list - though I've only seen it happen in Ubuntu 8.04.
You set it up in IPTables just like for any dual-homed-host.
Search these forums - there are many threads on the subject - doing this with wires.
Wireless is much the same using iwconfig instead of ifconfig. IPTables is identical, but for the interface names.
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