Note: please use the guide posted here HOWTO: Flash BIOS, The Ubuntu Way as the links in this guide no longer work.
I found a little document wich tells a way to flash your motherboard bios in a floppiless way.
Please be careful when flashing any bios because you can kill your mainboard
First thing you need is a dos/windows bootdisk image. You can get one here
Now you need to mount the image you will need to be root ie: sudo
mount -o loop -t vfat win98-boot.img tmp
Now you will need to get the latest bios image update from your mainboard manufacturer's site,and also get the latest awdflash available there.
Next copy the files into the dir where you mounted the bootdisk image.
Unmount dir after files are copied
cp AWDFASH.EXE biosupdate.file tmp/
You will then have a bootdisk image with all the necessary files.
let's make an iso image from the bootdisk image and burn it to cd.
Now you have an .iso ready to burn with your favorite burning application. (use a cd-rw no need to waste a cd-r with such a small file).
mkisofs -o image.iso -b win98-boot.img win98-boot.img
Now you just need to make sure that your cd drive is the first in the boot sequence. Go into your bios setup and make sure it's the first boot drive.
insert the cd in your drive, reboot and you'll be dropped into an old dos prompt like this one.
Step six (OPTIONAL)
This step is for award bios owners.
After you're in the dos prompt, you just need to run awdflash.exe, and follow the on-screen instructions. You can't save your old bios image though it's a small price for floppiless bios installs.
This howto: was made using this document by Davor Ocelic thanks goes to him for it.
Hope this helps.