This newsgroup is dedicated to discussion of the Toasted Circuits USB thumb programmer and its use.
This programmer is a free open source hardware device that can be used with the Arduino IDE (it looks like a "bootloader" but is actually a device programmer), or standalone with avrdude. It can be used to upload programs (sketches), flash bootloaders, and update fuse bits. As it is an open source project, you can also embed it into your own boards for use to upload sketches and for USB serial communications.
You can get a more detailed overview of the programmer in the Open Hardware Journal located at:
http://www.openhardware.org/journal/2011/11/