Tammy wrote a post a while ago about saving energy while preheating your oven. When I came to the part about it taking five minutes for her oven to get to 350 degrees, I thought "lucky her!" Mine takes around ten minutes. So often, I don't bother to preheat, I just turn the oven on when it's time to put the food in and call it good. Occasionally I need to add a few minutes to the cooking time, but it works out.
Sometimes, though, I need the oven to be hot when I put food in. That's when I use my broil function to preheat! I found that it can get up to 350 degrees in just a few minutes that way. Of course, I don't recommend you do that with a pan in the oven unless it is a broiler safe pan - I don't have my pizza stone in there while it's on broil, for example. My stoneware was not expensive, so I fear they'd crack at high temperatures.
For more kitchen tips, visit Tammy's Recipes.