boot - Multiple Operating Systems or ISO's Bootloader for a USB Stick?

I have no idea how to do this.

I have 7 iso's that I want to be able to easily boot from using a USB Stick and they are:

• Windows 7 Ultimate x86


• Windows 7 Ultimate x64


• Windows 8.1 x64


• Hirens BootCD


• Ultimate BootCD


• Windows XP Professional


• Ubuntu

Basically, I want to be able to boot my USB stick and instead of it just loading a single OS (like it does at the moment) I want a list of options ^ like above that I can choose and it will load that OS/ISO.

Any ideas how this can be achieved?