Laptop Power

• Kensington 33051, $60 at buy.com
• Kensington 33069, $95 at buy.com (supports AC as well as car)

USB Hub

• Kingwin Hi-Speed USB 2.0 Hub, unknown external voltage
• Trancend USB2.0 4-Port HUB, unknown external voltage
• IOGear 4-Port Hi-Speed USB 2.0 Hub, 5.0v external voltage (presumably 2amp, since each port could use up to 500amps?)
• IOGear 4-port microhub, also 5v
• D-Link 7-port mini hub (buy.com, newegg.com)

GPS

• Geko 201 (with interface cables) (with USB/serial adapter) (or buy bare cables for $5 each and wire them up the way I want)

USB ⇔ Serial / Parallel (and eventually to I₂C)

• BYTECC - Serial adapter
• BYTECC USB - IEEE 1284 bridge
• Available at Office Depot for $25 (labeled IPAQ Sync Cable)

USB keypad

• CompUSA has a Silver Targus Keypad which has an extra backspace and 000 key (making it primely suited to twiddler-emulation), for $20
• buy.com has a black keypad with the same extra keys available, IBM brand, for $24 shipped
• black keypad with 2 extra USB ports, $20
• Newegg has a black one for $15 shipped
• Twiddler 2 is available for $230 shipped

Universal Power

• Requirements
  • USB hub: 5 volts, 2 amps
  • Geko 201: 3 volts
  • Laptop: 20 volts, 3.5 amps
• BWR-5/6-3.3/7-D12 (12v in, 5V 6A and 3.3V 7A out), $70
• 100W DC-DC ATX
• 100 watt EPIA power supply (specs)
• While the ITPS seems to be popular when combined with a mini-ITX power supply in the car, it may be simpler and cheaper for me to simply use a 12v LDO regulator, but only turn power on to the perhipherals when a USB connection from the laptop is detected (which makes a ton of sense, really...)

USB Audio

• Griffin iMic (supposedly works great on linux, this person concurs)
• Sound Blaster MP3+ (external USB) available at CompUSA for $60, or online for $50 shipped. Or... available for $38 after a $20 rebate from buy.com.
• Sound Blaster Extigy (external USB) online for $128 shipped

Other

• 4-port cigarette expander (picture)
• ATX shutdown controller for car
• 12-volt LDO regulator