Thanks to saikee and others for getting me started thinking along these lines. About six months ago my wife bought an Averatec AV3715-EH1 laptop with windows xp home preinstalled. I only learned after the fact to my disgust that no system restore or install disks were included, but rather something called Recover Pro which resides on its own inaccesible partition and can be invoked pre-boot to restore the factory settings or designated periodic restore points. The latter can only be set during a 30 day evaluation period, unless you buy a license. My wife soon began to have typical windows complaints until I wondered what was wrong with this little laptop. After some frustration I found a way to run linux on it which took care of all of her computing needs and most of mine, and makes it a happy lappy. I still need windows for some part time work related apps not of my choosing. The things I like most about my solution is that no partitioning of the windows hard drive is required, its mbr remains untouched, and no other boot media such as floppy, cd or flash drive is required.
1. With the install cd loaded on the laptop, I installed MEPIS 6.0 to a usb 2.0 80G hard drive, formatting 20G as ext3 and leaving the remainder as FAT 32 to serve as a backup/storage partition. I installed grub to the usb hd mbr by the defaults, then added "rootdelay=10," to enable booting the usb hd. Here is the MEPIS grub menu.lst file:
timeout 15
color cyan/blue white/blue
foreground ffffff
background 0639a1

gfxmenu /boot/grub/message

title MEPIS at sda3, kernel 2.6.15-26-386
kernel /boot/vmlinuz-2.6.15-26-386 root=/dev/sda3 rootdelay=10 nomce quiet vga=791

title Windows at hda1
rootnoverify (hd0,0)
chainloader +1

kernel /boot/memtest86+.bin

I left the windows option, just because it was there, though useless in this setup.

2. I installed grub for dos, putting these files at the top of c: grldr, menu.lst, and copies of the MEPIS vmlinuz and initrd files, the latter before realizing it probably wasn't necessary. Then I added this line to the windows boot.ini file:
Finally, I edited the grub for dos menu.lst file as follows:

# Sample boot menu configuration file

# Boot automatically after a minute.
timeout 60

# By default, boot the second entry.
default 1

# Fallback to the first entry.
fallback 0

title Windows XP
unhide (hd0,0)
rootnoverify (hd0,0)
chainloader +1

# For booting Linux

title MEPIS at sda3, kernel 2.6.15-26-386
kernel /vmlinuz-2.6.15-26-386 root=/dev/sda3 nomce quiet vga=791 rootdelay=10

title Puppy
rootnoverify (hd0,0)
kernel /vmlinuz root=/dev/ram0 PMEDIA=idehd
initrd /initrd.gz

I left the windows option, but I can't see any use for it except if someone changed their mind about booting linux. The third option is for Puppy linux whose files are embedded in the windows hd by the "coexist" install option, but that is another story. So when the laptop starts to boot, you get the options of going to windows or grub. If you select grub, then you get the options of going to MEPIS, Puppy or back to the windows option. There may be other ways of doing this, even more elegant, but it works for me and my MEPIS lover.