some comments on the "longest" word, dxb:

1: floccinaucinihilipilification, the longest word in OED1, was coined ca. 1741, long enough before OED1 to make it into OED1. it's actually fairly easy to pronounce:
'floksi 'nossi 'nihili 'pilifi KAY shun
it's a great word to throw out in conversation, once you've mastered it.

2. that other, medical word wouldn't be included in any general dictionary of mine, but it is the longest word in OED2.

3. then there are those ridiculously long protein names which some, like Mrs. Byrne, include fatuously (and perhaps fastuously).
here's a previous thread on this subject:
http://wordsmith.org/board/showflat.pl?Cat=&Board=words&Number=37369

also, http://wordsmith.org/board/showflat.pl?Cat=&Board=words&Number=12898

heeere's Quinion!
http://www.quinion.com/words/weirdwords/ww-flo2.htm

(it's also my watchword at wwftd :)