Seems like everyone is shifting their own ISP programmers from COM and LPT ports to USB. And there is a reason for this – computers arre getting mobile, LPT and COM ports becoming obsolete. But almost everywhere you can find USB port, so it is logical to have USB programmer rather then old style.
ladyada have developed very tiny USB ISP programmer which also can serve as USB-SPI interface. Thisis really low cost and low component count programmer built under Attiny2313 AVR microcontroller. It is compatible with AVRDUDE and AVRStudio and works under Windows, Linux and MacOS.
This is not the fastest programmer but it can guarantee write speed of1 Kb/s and read speed of 2Kb/s. Other good feature is that it comes with both – 6 and 10 ISP connector types. You can build this adapter easily as all necessary files are available for download, or you can simply order a kit.