Recently (like as of an hour or two ago) i have (finally) begun messing around with tape loops. cassette tape loops mind you, because my little portable reel to reel machine doesn't actually go round and round anymore (though it does make excellent distortion.

so anyway, i got online to get some specifics, i mean the idea is simple, but, well, its handy to know just exactly how short to cut the tape ribbon before you start. Also, and more importantly, there is more than just one way to loop cassette tape. there is the simple, and obvious way; just cut a short length (like 14.5 inches maybe?) and wrap it around the reels and such in a circle. Then there is the chandler loop, which is more complicated, but has the extra benefit of actually working. It looks like this: a decent discussion can be found here: http://ofsoundmind.wordpress.com/2006/12/
(scroll down, you'll see it).

it should be 14.6 inches. check here :http://en.wikibooks.org/wiki/Making_Cassette_Tape_LoopsCassette_Tape_Loops for even more details

Mind you, i've yet to actually record anything on my new tape loop, but it does seem to go round and round quite nicely.