Now updated and working in recent android versions!
DOES NOT START ON BOOT.
DISPLAYS IN STATUS BAR.
If you want a lock disabler that starts on boot and doesn't display in the status bar, then DO NOT DOWNLOAD THIS APP. The app you want is named "No Lock" and is probably shown below under "related apps".
Simple program to disable "slide to unlock" on phones that don't have that option. Known to work on Droid and Droid 2.
This app leaves an icon on your status bar under "ongoing" to make it clear the lock is disabled. As hinted at above, if you would rather use a widget, or have no UI at all, check out the app "No Lock" instead.
Known bug: Sometimes the lock will be re-enabled but the app will still be running. Attempts to track this down have failed. If it happens, turning it off (click the notification to clear it) and back on should restore functionality.
Also, when the screen lock is disabled, the volume and camera buttons may turn your phone on. This is just how the OS rolls, and isn't something I can change or control in any way. I consider it a feature, and I wish the nexus 5 still did it.
Updated to work once again on recent android releases, KitKat at least