On Fri, 14 Dec 2007 14:17:47 -0800, plenty900 wrote:

> Is there a bootable USB flash version of the Slackware installation
> discs?

If there isn't, you can make your own.

> I want to install on a system that has no optical drives but can
> boot a thumbdrive.

You should get a good start with your reading here:

http://www.pendrivelinux.com/