All SCSI drives should work if the controller is supported, including optical (MO), WORM, floptical, Bernoulli, Zip, Jaz, SyQuest, PD, and others.
Panasonic MO (combines a CD-ROM drive and an optical removable disk). You have to set a switch when configuring the kernel to get both part work at the same time.
Parallel port Zip drives here
Parallel port Avatar Shark-250 here
Removable drives work like hard disks and floppies, just fdisk / mkfs and mount the disks. Linux provides drive locking if your drives support it. mtools can also be used if the disks are in MS-DOS format.
CD-R drives require special software to work. Read the CD-R Mini-HOWTO.
Linux supports both 512 and 1024 bytes/sector disks. Starting with kernel 2.1.32 Linux also supports 2048 bytes/sector. A patch to kernel 2.0.30 is available at here.
The 2048 bytes/sector support is needed for
Fujitsu magneto-optical disk drives M2513
Starting with pre-patch-2.0.31-3 IDE/ATAPI internal Zip drives, flopticals and PD's are supported.