Free MultiBoot Loaders
http://www.thefreecountry.com/utilities/multi-boot-managers.shtml

If you want to boot more than one operating system ("OS") on a single computer, a boot manager or multi-boot loader comes in handy. The boot loader allows you to easy create and configure a boot menu so that you can select which OS to boot,

GAG The Graphical Boot Manager
    GAG boots up to 9 operating systems from either the primary or EXTENDED partitions. It installs itself into the boot track, has support for a timer to boot a default operating system, includes password-protection for the configuration menu as WELL as for individual operating systems, has a SafeBoot system where your hard disk is booted even if GAG is overwritten, and supports hard disks of up to 4 terabytes. It is licensed under the GNU General Public License.

GNU GRUB - Grand Unified Bootloader
    This boot loader, used in some Linux distributions by default. It is distributed here in source form; you probably already have the binary version if you are running Linux. It is able to boot multiple operating systems, including Linux, Windows, MS-DOS, etc.

Smart Boot Manager
    Smart Boot Manager is an OS independent boot manager that searches for drives and paritions, and automatically includes bootable partitions into its boot menu. It includes a SCHEDULER that allows you to boot a particular system at a preset time. It has the ability to boot from CD-ROMs, boot the default boot record after a delay if no keys are pressed within a specified time, place keystrokes into the operating system's key buffer prior to booting it, etc. It also supports the password-protecting of partitions, drive and the administrative screens.

XOSL (Extended Operating System Loader) Boot Manager
    XOSL installs itself into a dedicated partition (which you have to create yourself). The initial installation has to be done from real mode MS-DOS (not a DOS prompt window running in Windows). Operating systems that it can boot INCLUDE MS-DOS, FreeDOS, Linux (with LILO), Windows 95/98/NT/2000, Solaris, BeOS, etc. You can password protect certain boot items, set a automatic boot timeout, install up to 24 operating systems, swap drives, etc.