Modern Device has a cheap kit for this purpose:
ByVac has a similar solution, but for I2C. The chip doesn't require any external components except a potmeter for contrast adjustment. I have one and it works fine, but I had to learn a bit about I2C to use it.
The advantage of using I2C is that the serial port is free, which makes things easier when developing. The disadvantage is that the Wire-library (needed for I2C) is big, it use around 2400 bytes of flash.