The USBtinyISP is an inexpensive kit that emulates the AVRIsp in-system programmer. It's an inexpensive way to start "burning your own code"!
The USBtinyISP is an inexpensive USB-based AVR programmer and SPI (Serial Peripheral Interface). What that means is that you can plug this into your USB port, and have it program practically any Atmel AVR microcontroller. Here's what it offers:
Developed by Adafruit Industries, this project is open-source, so you can review the circuit, software, and feel free to modify it suit your needs with full permission (under the Creative Commons license 2.5 Attrib./Share-alike).
Note: USB A-B cable is not included