at the moment, my most used/usefull machine is an 030 based a1200 with a 4gb compact flash and a 10Mb pcmcia network card.
WHDLoad classic amiga gaming (put floppy disk games on harddisk), basic web browsing, pop3 email access.
mp3? yes, with 040/060/PPC for decent quality. for anything less CPU wise, decode it to a WAV file and play that back instead. or get a floppy/parallel/clock port MP3 decoder card from individual computers..
DVD? erm. kinda. with 200mhz PPC603 dumping 8bit greyscale out to a bvisionPPC graphics card and AC3 decoding you might be able to put up with it. i remeber still using a DVD decoder card with a 400mhz PC...
Web? mmmmyeah... basic web is fine with aweb or ibrowse. a more modern web expirience can be had with Origin Web Browser, but it wants an 040/060/PPC and OS3.9+BoingBag2 with 64+Mb ram and possibly a GFX card as a starting point..
