• USB (Universal Serial Bus)
• IEEE 1394, 1394-1995, 1394a-2000

Chips

• FT8U245AM (and issues about speed and smarts covered here).
• EZ-USB family of chips, apparently inexpensive for hobbyists, and widely used in industry. Features code-downloading via USB, high-speed pathway between external I/O and USB, and an I²C interface. Some people even sell nicely prepackaged (devasys, usbsimm, activewire, keyspan, cypress) versions of the EZ-USB micros. And there's linux drivers.
• Many other microcontrollers with a USB interface.

Corporate Links:

• Philips
• Texas Instruments
• Lucent

Indexes

• Beyond Logic
• USB Central

Reference

• USB Design by Example: A Practical Guide to Building I/O Devices and its free precursor, Learn USB by Doing
• USB Complete: Everything You Need to Develop Custom USB Peripherals, Second Edition
• Circuit Cellar articles - Working with USB, USB Chip Choices-2000-July, USB 4-part Primer-CDROM4 1, 2,

Hobbyist USB projects

• USB Pulse Box for BeOS
• FPGA on a Rope
• USB-storage-device MP3 player
• PSX & N64 controller -> USB

Hobbyist USB usenet threads

• [EE]: USB options for a hobbyist