The Motorola Freecharge is essentially a portable battery pack that can be charged with the hand crank. It'll give you 3.0-3.6 volts depending on how charged it is. The battery inside is of the NiMH type, and has a similar capacity to a typical cell phone battery.
Here is a picture:

At retail, these things are fairly expensive. Trusty old Ebay seems to have some cheap ones available.

So at this point there are a few things you can do with this:
-Solder some bright LEDs together, add a resistor and a switch, and you have your own hand crank flashlight
-Add some circuitry to get it to power your ipod
-Power your DS/gameboy/PSP
-Turn the crank on it solely for the physical workout
-Build a cheap radio

The radio idea sounded nice to me. Now let's go on a diversion hack. Ever heard of HitClips?

It's a crappy music player from 2001 made by Tiger Electronics. It plays 1 minute song clips from cartridges, like this one:

On the other side of these cartridges are some terminals. To find out what they do, I took apart a hit clips player myself:

Wow, that's some ghetto design on Tiger Electronics' part. Not even a single resistor. Just a speaker, battery pack, and play button connected to the interface board. That means that all of the device's logic is implemented right on the cartridge! After a few minutes of following traces on the small PCB, I give you the pinout to these cartridges:

Tiger Electronics also made an FM radio receiver for their hit clips players:

Here is where the diversion ends. We know the pinout to the cartidges, and to the Motorola Freecharge. Add a speaker, and we could have our own wind up radio! And that is what I did:

The only pins I used on the radio receiver was power, ground, and the two speaker pins. Nothing else was needed. I even got the speaker from a broken TV set.

If you attempt to build this yourself, there are a few things you could do different:
-Add a potentiometer to adjust volume
-Add a headphone port
-Add power terminals
-Make it chargable from a wall adaptor

Winding it for 30 seconds gives me about 8-10 minutes of operation. It's actually pretty cool. One of my friends went as far as calling it sexy.