Considering that big families require big turkeys, and big turkeys require lots of oven time, baking space really comes at a premium at my house. Jewish as we are, Christmas day has become synonymous with Thanksgiving 2.0, and similarly, things get made days in advance so that the bird can roast on its own, unadulterated by the pies and potatoes that would otherwise try to nestle alongside it. Despite our planning, it's sometimes impossible to sidestep the inner-oven traffic jam, which is why I was excited to find this 3-Tier Oven Companion by Nifty ($19.99 at Bed Bath and Beyond).
Given that you have a standard-sized oven, the 3-Tier rack allows you to make better use of your space by adding more vertical space without compromising the bird's. This way, you can stack up the various potatoes and greens that'll be served alongside your clucker (or ham, or whatever festive protein takes up the bulk of your oven space). Since good airflow is necessary for even cooking, it's more useful towards the end of your cooking time, when things just need to be kept warm.
I do have one warning: Resist the temptation to put pies on the racks while your turkey is cooking. Nothing will ruin them faster than the infiltrating poultry aromas.
It's also key to note that city-dwellers with narrower than normal ovens won't get much use out of this. My Manhattan oven, for instance, is too narrow and short to benefit from the system, though the dimensions work well anywhere else. Storage, however, is kind to smaller kitchens—the racks dissemble and fold up quite easily, and Velcro rings keep everything together and in place.