Hardware

I didn't think it was possible to install m0n0wall to a flash drive (thumb drive) since this website lists IDE and compact flash cards as being compatible for installs with nothing else listed. I'm currently running m0n0wall off a 4gb flash drive and it works great. Why isn't there more information regarding this type of install?

If by "thumb drive" you mean a USB stick type of thing, then sure, installing m0n0wall onto one is possible. All you need is an OS and software that supports writing the image file to the USB device. Just about anything can do this these days.

However, once you have m0n0wall installed on the USB stick, it gets a bit narrower since the primary target for m0n0wall is small embedded computers. Many of these do not support booting from USB.

Ordinary modern desktop type PCs will have no trouble booting m0n0wall from USB.