Behold the Zalman ZM-VE200 (branded internationally as IODD) – a 2.5″ HDD enclosure that has a neat trick up it’s sleeve – the ability to present .iso files written to its _iso folder as if they were a CD/DVD i.e. Virtual optical drive technology. Saves carrying around a pocket full of scratched cd’s. Just download the .iso and boot off it. No burning to CD first, and perfect if there’s no cdrom drive present (but requires boot from usb capable bios).
It’s worth mentioning the default firmware supports ntfs out of the box – i.e. unless the drive is formatted with an ntfs filesystem, the virtual cdrom drive folder _iso will not work. ntfs is a good choice since both windows and linux (desktop distros at least) can read it these days and unlike fat32, it supports large files – necessary for storing bootable dvd isos. If fat32 is absolutely necessary for universal compatibility though, you can download and install the firmware to make it work in fat32 mode instead of the ntfs mode that it ships with. If I recall, this involves downloading the firmware file to the _iso folder and booting off it – but check the documentation on the zalman website. It’s a simple procedure, but will limit the size of the iso that can be written to the disk. Having converted mine to fat32, I might go back to ntfs firmware. I have multiple storage devices so there’s always something formatted with fat32 kicking about if necessary.