In addition to the previous reply:
What about external cd-rom?
There are some proprietary amiga PCMCIA CD-ROM drives, you might be able to find it from ebay. Mind you, the interface between the drive and the controller was often proprietary back then, so you can't swap the cd-rom drive if it dies.
What about dvd-rom?
No, unless if you go thru the SCSI-interface route. PCMCIA is very slow still, so don't expect miracle speeds. Forget playing DVD video thru it (even if your system would be fast enough otherwise).
Any other items that are usually used on a pc work on an amiga?
Generally, no.
The devices that work need to either be specifically made for amiga, or drivers need to exist for the hw. Also, the electrical differences of the PCMCIA spec revisions limit the cards you can use, namely Cardbus (32bit) devices won't work.
