DIY Tape Delay

Recently my school has started to clean out it's media centre, and this means that they are now getting rid of tons of obsolete equipment from the 70s and 80s. Among the video editors, slide projectors and keyboards are several tape decks.
What I was wondering was is it possible to use any machine/s that can play tapes (from reels or cassette) to make into a tape delay/chorus/flanging machine, or can one only use reel-to-reel recorder and not boomboxes or tape decks and the like?

possible? of course! easy? not likely.
http://gadgets.boingboing.net/2008/05/01/diy-tape-delay-machi.html

Take two tape machines and go Frippertroniks. Its so funny to do. And you can get really interesting sounds out of it.

Electro-Harmonix made a 16-seconds delay pedal that they called Fripp In the Box.
According to Robert Fripp he phoned them up and asked if he could have one.