not sure if this one has been mentiioned but here it is:

Commell LV-670 Pentium 4 Mini-ITX Mainboard $189.00

LV-670 Specifications
Processor Supports Pentium 4/Celeron socket 478 - up to 2.8ghz
533/400 MHz FSB
Chipset Intel 845GV north bridge
ICH4 south bridge
System Memory 1 DDR266/333 SDRAM socket
Up to 1GB memory size
VGA Integrated Intel Extreme Graphics Core
Expansion Slots 1 PCI
Onboard IDE 1 Ultra ATA 100 (40 pin)
1 Ultra ATA 100 (44 pin)
Onboard USB 2 USB 2.0
Onboard LAN Intel ICH4 and 82562ET 10/100
Onboard Audio Intel ICH4 6-channel AC'97 with SPDIF
Onboard TV Out Chrontel CH7011 encoder with AV and S-video
Onboard 1394 1 Agere FW323 IEEE 1394 controller
Back Panel I/O 1 DB15 VGA port
1 S-Video port
1 TV-out port
1 LAN port
2 USB 2.0 ports
1 IEEE1394 port
1 PS2 mouse port
1 PS2 keyboard port
1 Parallel port
1 SPDIF
3 Audio jacks: line-out, line-in, and mic-in
Onboard I/O Connectors 2 IDE connectors (40 pin & 44 pin)
1 FDD connector
1 IEEE 1394 connector
2 USB 2.0 connectors
1 RS232 serial connector
Wake-on-LAN connector
1 CIR/SIR IrDA connector
1 Front panel audio connector
1 CD Audio-in connector
2 Fan connectors
ATX style with P4 power connector
BIOS Award BIOS 2/4Mbit flash memory
System Monitoring & Management CPU voltage monitoring, Wake-on-LAN, Keyboard Power-on, Timer Power-on, System power management, AC power failure recovery
Operating Temperature 0 ~ 60°C
Form Factor Mini-ITX (17cm x 17cm)
Includes ATA 133 flat cable (40 pin, 80 conductor, 3 connectors)
ATA 133 flat cable (44 pin, 44 conductor, 2 connectors)
Back plate
Installation CD
User Manual
Dual USB 2.0 port connector
Serial port connector
Audio jacks connector
FDD cable