Nearly every smartphone lives and dies by its touchscreen, and if your touchscreen goes kaput, it's probably time to get a new phone or replacement screen. Until it arrives, consider reader Metalgeek's clever "iPhone Braille Adaptor".
Last year, my iPhone 3G's LCD died, but the touchscreen was still working. I could (by memory) slide-to-unlock, enter my passkey and open the phone app. Saved my butt while I waited for a new LCD to arrive.
So if the same thing's happened to you, and you're...
A) Waiting for a new LCD to replace it (trust me, it's easy.)
B) Saving up for a new iPhone (or better yet an Android!)
... print out what I call an, "iPhone Braille Adaptor". Only took a few minutes to whip up. You've got the slide-to-unlock, unlock keypad, the default phone app icon location, the keypad button in the phone app, and the phone keypad itself.
I've tested, and it works fine if you print it on thin office-grade paper. Just tape it on with scotch-tape at the top & bottom, and you'll be able to get by until that new LCD/Phone is in your hands.
Obviously the same idea could apply to most touchscreens — you'd just need a different template to fit your device. Get Metalgeek's original template here.