Vastly Improve Your Lockscreen with WidgetLocker
Most OEMs don't care much about the lockscreen in Android. Some, like Samsung, offer you the date and time, plus a swipe to unlock function. HTC takes it a bit further as of late by letting you instantly launch your four favorite apps, right from the lockscreen. If you want the utmost in customizability for your lockscreen, try WidgetLocker. It's a $1.99 app that grants you a tremendous amount of flexibility: add sliders to quickly launch apps; add widgets to keep an eye live information; or choose to unlock your phone with a particular hardware button, thus circumventing the "slide to unlock" action altogether. The app works best if your device is rooted.