Could you possibly do two NIC teams each connected to separate switches? But if you have 2 ports available on each switch why don't you trunk?
In separating the teamed adapters you can do adaptive load balancing which works on outbound traffic. I'm guessing you want to load balance incoming traffic. So we're back to my opening paragraph, 2 teams or a trunk.
You should probably tell us hardware, OS, and purpose of the server, network hardware and configuration. Maybe someone has better or simpler ideas of how to accomplish what it is you want to do.
