The Arduino ICSP Programmer allows you to create your very own Arduino board, simply connect the programmer to your Arduino compatible board and start uploading your boot loader or sketch.

On the other hand if you already have the Arduino, fetch the avr.isp.03 firmware and AVRdude. Then program a device, for example an ATtiny13 using the Ardunio as the programmer.

Arduino explain: “The Arduino ISP is an In-System-Programmer that is used to program AVR microcontrollers.

[Minifloat] is using his TI Launchpad development board as an In-System Programmer for AVR chips (translated). There are a ton of homebrew AVR programmers out there, and using an Arduino for ISP ...