If you look at your lock screen and see wasted screen real estate, then you should check out ScreenLab from Lemonskin. ScreenLab allows you to design a lock screen wallpaper filled with useful information. Because it uses the lock screen, ScreenLab can display these details to anyone, even when they don't have the passcode to your iOS device.
ScreenLab allows you to choose a background for your lock screen and then add items to make it more personal. You can add contact information in case your iOS device is lost, a calendar to help you with dates and a checklist to keep track of important tasks. There's also an option to put a photo with borders and a block of text that you can use to say anything you want to the world.
ScreenLab lets you move and rotate each element on the screen so you can get the arrangement that you like. You can also change the style and color to match your background. The iPad app has a nice editing screen that helps you design a lock screen that looks great in landscape and portrait orientation.
When you are done, you can preview your lock screen and then export it to your camera roll. Because of the way iOS works, you then have to manually set the lock screen image using the Photos application. The iOS lock screen image is also static, which means you have to create a new image each time you want to change the information on your screen. It's a slightly cumbersome process, but doable for folks who want more than just a pretty photo when they wake up their device.
ScreenLab is available for US$1.99 from the iOS App Store.