Having trouble keeping pace with the unyielding march of smartphone technology? Sick of the social pressures to upgrade your perfectly functional communications gadget every seven seconds? Well, it's time to fight the man and follow in this guy's footsteps by constructing your own phone! Wow your friends with your ingenuity and new-found hipsterness.
The phone pictured here is from an Instructables tutorial by a user called "mellis". The chassis is made from laser-cut plywood, while the internals consist of various electronics components (surprise!) including an Quectel M10 chip for GSM/GPRS connectivity.
So just how feature-packed is it? For something with a single line of LCD output, very. According to the tutorial, it can "make and receive phone calls and text messages, store names and phone numbers, display the time, and serve as an alarm clock." Unfortunately, it lacks the ability to play Infinity Blade, but you probably already knew that.
While there's a list of the hardware required, there's no cost breakdown of components, but I imagine you could put it together without too much outlay. (Edit: there is indeed a cost breakdown: $US135.46 -- thanks forphucsake)
Even if you don't use it as an actual phone, rocking up to your local phone repair place and pulling this out for laughs would be worth the effort alone.