Hmmm, the only problem is the wireless ones require a power supply. You could either go with a pair of innner ear headphones which are designed to have a short cable length, learn the art of cable wrapping (something I did when taking my sanheisar ones around), or see if you can buy a set with replaceable bits and replace the long cable with a shorter one. I'd assume this is possible, ---- sinse I think my sanheisar cable is about 7 feet long, but i'm not sure sinse the length has never caused me trouble.
what I used to do with my portable Cd player was get a litle rectangular leather case which zipped up along the long face of the rectangle at the top like a tub of butter.
this way, I took out the headphones, but most of the wire stayed in the case along with the player, and I just needed to keep the case in my bag, or on my lap or wherever.
Sinse my new mp3 cd player has small inner ear headphones though, i'm not quite as worried about cable length at all.
Btw, if your wearing cut out headphones, you shouldn't hear the computer's fans or indeed much else (my parents had to always tap me on the shoulder to get my attention). I'm just wondering though, what's wrong with the sound of cmputer fans? Personally, I like the fan sound, if it's smooth and even I know my computer is working okay.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)