If you are interested with booting operating systems from a USB Flash device, check out RMPrepUSB.com. This is the home of the kick arse utility called RMPrepUSB that will make your USB device bootable a snap using either syslinux or grub4dos boot managers. Using this utility, I was able to take a 2GB SD card and my Zonet SD card reader and create a WinPE 3 x64 bootable USB flash device using Make_PE3 and RMPrepUSB with great ease.
Another cool thing I discovered is the ability to test booting your USB flash device with QEMU Manager (tutorial here). The advantage to this is that you can take screen shots of the early stages and you don’t have to keep rebooting your computer all the time to see the changes you made. There are over 50 tutorials on this web site, from installing Windows XP from a USB flash device to resetting passwords.
Speaking of USB flash devices: ISOStick. This is a project they are trying to get off the ground and is worth watching. It is a USB flash device where you drop an ISO file unto it and then you can boot from that ISO, without any of the messy configuration necessities of grub4dos or syslinux.
– Soli Deo Gloria