I did a google search for your laptop and this is the result taken from the Gentoo wiki. Pay particular attention to the things that work section- usb.
This guide is about how to install Linux on the Asus A6Km laptop.
 Hardware overview
CPU AMD Turion 64 Mobile Technology, MT-32, 512kB L2 cache, 1.8Ghz, 25W
Motherboard SIS 756 + SIS 964L
Hard disk IDE UDMA-100 80 Gb / 5400 RPM.
Cd-rom IDE, DVDÂ±RW+DL
Video NVidia GeForce 7300 Go 64 MB with TurboCache supporting up to 256MB, TV-out and external monitor port
Display 15.4" WXGA Color Shine LCD Technology, 1280 x 800 px
PC Card 1 x Type II PCMCIA 2.1 compliant
Cardreader Ricoh R5C822 SD/SDIO/MMC/MS/MSPro
LAN Realtek RTL-8169 10/100/1000 Base-T
WIFI Broadcom Corporation BCM4318 802.11g Wireless LAN Controller
Modem SiS AC'97 Modem
USB 4 ports, USB 1.1 and 2.0
FireWire 1 port
Infrared 1 port, IrDA v1.1
Parallel 1 port, EPP/ECP
Audio 1 Line In, 1 Line Out, 1 Microphone, 1 Optical out, AC'97, Audio-DJ
 lspci output
* 00:00.0 Host bridge: Silicon Integrated Systems [SiS] Unknown device 0756 (rev 02)
* 00:01.0 PCI bridge: Silicon Integrated Systems [SiS] PCI-to-PCI bridge
* 00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS964 [MuTIOL Media IO] (rev 36)
* 00:02.5 IDE interface: Silicon Integrated Systems [SiS] 5513 [IDE] (rev 01)
* 00:02.6 Modem: Silicon Integrated Systems [SiS] AC'97 Modem Controller (rev a0)
* 00:02.7 Multimedia audio controller: Silicon Integrated Systems [SiS] AC'97 Sound Controller (rev a0)
* 00:03.0 USB Controller: Silicon Integrated Systems [SiS] USB 1.0 Controller (rev 0f)
* 00:03.1 USB Controller: Silicon Integrated Systems [SiS] USB 1.0 Controller (rev 0f)
* 00:03.2 USB Controller: Silicon Integrated Systems [SiS] USB 1.0 Controller (rev 0f)
* 00:03.3 USB Controller: Silicon Integrated Systems [SiS] USB 2.0 Controller
* 00:09.0 Network controller: Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller (rev 02)
* 00:0a.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev b3)
* 00:0a.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C552 IEEE 1394 Controller (rev 08)
* 00:0a.2 Class 0805: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 17)
* 00:0a.3 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 08)
* 00:0b.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8169 Gigabit Ethernet (rev 10)
* 00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
* 00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
* 00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
* 00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
* 01:00.0 VGA compatible controller: nVidia Corporation Quadro NVS 110M / GeForce Go 7300 (rev a1)
 The Howto
As this didn't resemble a howto or a guide (rather an incomplete list of hardware), I thought I would add to it as I have this laptop and run Gentoo 2006 amd64. (Submitted by Appleman1234)
 Things that work
CPU: The CPU works and supports frequency scaling. Frequency scaling requires the modules, freq_table, cpufreq_userspace, powernow-k8 and a application like cpudyn or powernowd.
ACPI: ACPI works with kernels greater than 2.6.16-rc3, before this it required a BIOS downgrade, a change of DSDT, or removing usb support from the kernel. The easiest solution is to use a newer kernel. It helps if you emerge an acpi dameon like acpid or powersaved and add it to the default runlevel. The ASUS-ACPI is said to work with correct setup according to the Italian Gentoo Wiki, I am yet to test this but will do so.
Apparently more hotkeys (more then just brightness and lcd off) can be accessed by using asus-hotkeys  and the definition file . Yet to be tested.
Wireless: Wireless works with bcm43xx module in the 2.6.17 kernel. You have to use fwcutter to get the firmware and install it properly though. (See This Gentoo forum post for instructions ) The code for this native driver is a little buggy (They are working on fixing it), so wireless may play up from time to time. Networkmanger and Knetworkmanager now work
, just be careful with udev and dbus.
In order to make it work again: modprobe -r bcm43xx modprobe bcm43xx iwconfig eth1 essid Youressid ifconfig eth1 up
You can also use ndiswrapper just make sure you use the 64 bit windows drivers. (For more information go here)
In kernel 2.6.20 and latest udev all work at the box(Need only firmware. I get this from ASUS CD.).
Ethernet: The wired ethernet works correctly with the r8169 module. But if you want to change mac address first you need to apply this patch
Graphics Card: The nvidia module works flawlessly with xorg 7.0. To get it emerge nvidia-kernel and emerge nvidia-glx. If you have xorg 7.1, it still works (you just have use the emerge --nodeps option) but their are some font drawing problems. I changed a subhinting pixel setting in KDE and now the only applications that are affected is sometimes Firefox and Wine applications. If you don't want to downgrade your X and have no need for 3D support, I suggest you just use the nv driver instead. Update: No problems in xorg 7.1 now after nvidia update and beryl provides xgl effects using nvidia drivers.
USB: USB works provided you load the right modules. (ohci-hcd, ehci-ocd, etc)
IEEE1394: Should work, haven't tested.
PCMCIA: The module is yenta_socket.
Ricoh Co Ltd R5C822 MMC / SD Card reader
A driver for the MMC / SD card reader has been in the kernel since 2.6.18 (sdhci). Both SD and MMC cards work
Sound: Sound now works, with recent versions of ALSA. The module is snd_intel8x0. The was a big issue, bug with this card in older versions of ALSA, this has been resolved.
Modem: It should work with linuxant drivers and it might work with the Smartlink drivers, but I haven't as of yet tested it.
Webcam: A driver for the device is currently under development [ http://syntekdriver.sourceforge.net/
] (thanks to thothonegan and maxxer for pointing The driver is finally at version 1.0 release, and currently works for most V4L applications and some V4L2 applications.
lsusb of this camera
Bus 001 Device 002: ID 174f:a311
iManufacturer 1 Syntek Semicon.
iProduct 2 USB2.0 Video
Infrared: Works under lirc using the lirc-sir driver with irq=3 and io=0x2f8. Make sure it is loaded before the serial driver (make the serial driver module) or lirc wont be able to get it. Haven't tested IrDA communication, though it should work fine with the irtty-sir driver. More information here: Asus a7j lirc RC
I will add more information and detailed instructions for things when I get time.
The following are good resources: