|I'll point you in the right direction. What you're looking for is either: MLT or SMLT|
MLT = Multi Link Trunk
SMLT = Split Multi Link Trunk
However, you said, "How can one configure a LAN to have redundant links to a single NIC or MAC address? "
The problem with your scenario is, you cannot provide redundancy to a single NIC because if it fails, or the device it's a part of fails, then you lose your connection....even if you have an MLT or SMLT configured.
Take where I work for example. We have dual 8600 Nortel Passport core switches as the heart of our switched network. They are connected by dual IST's (inter switch trunk) which allow them to communicate with each other and provide redundancy. Should the primary fail, it switches over to the other one so fast, you don't even notice a hiccup on the network.
Connected to the core switches are our stacks of switches. I'm only going to discuss the "client stack" that consists of 5 Nortel Baystack 5510 switches connected via cascade cables. This allows them to behave as one big single switch.
The client stack is connected to our core switches (Core A and Core B) via an SMLT. Because of the way this equipment works together, the two links aggregate bandwidth so that I have 2 GB's of bandwidth between the client stack and the core switches.
One half of the SMLT connects to Core A, the other to Core B. This provides redundancy. Should Core A (the primary) fail, all data travels to the client stack from Core B. Granted, I lose 1 GB of bandwidth, but the remaining 1 GB is still an awful lot.
Anyhow....on the client stack I have port 48 on unit 2 as one uplink and port 48 on unit 4 is the other. Should unit 2 fail....all remaining units are able to continue communicating via the uplink in 4/48. Again, bandwidth drops to 1 GB but, the fact that all other switches, but the broken one, can continue to communicate means we have redundancy in both directions (ie: broken core switch or broken stack member).
So you see, it's nearly impossible to actually build in any redundancy with a single switch connecting to a single switch. At best (depending on the equipment you're using) you can double the bandwidth between switches.