Simple, easy to use and inexpensive considered.
In device manual:
The 8051prog™ programmer is a great tool used for programming 8051 microcontrollers from Atmel®. As a low-consumption device,
it is ideal to be used with notebooks. It’s unique design and simplicity make it a very popular tool among beginners and professional
users alike. The 8051prog programmer communicates to the microcontroller through a USB cable which is also used for powering
the programmer. In order to use this programmer, it is necessary to have the 8051Flash program and the appropriate driver, provided
on the product CD, installed on your PC. After that, you can use the 8051prog programmer and a hex code generated in any 8051
compiler to load the program into an 8051 microcontroller.
The 8051prog programmer is built into all Mikroelektronika’s 8051 development systems. The same programmer is also available as a
stand-alone device used for programming 8051 microcontrollers built into (soldered on) the target device.http://www.mikroe.com/8051prog2/