From www.word-detective.com
ear Word Detective: A fellow co-worker and I are discussing the proper pronunciation and
             spelling of the elusive "kattywampus." We desperately need help to resolve this perplexing
             problem. -- Alissa and Jenifer, via the internet. 
             Desperately? You "desperately" need the spelling and pronunciation? Have the two of you
             been cornered in a broom closet by a ferocious spelling bee? Oh well, mine not to reason
             why, I suppose. Besides, it sounds as though you folks are doing a bang-up job of wasting
             company time, and I'm always up for that. 
             Unfortunately, and I say this with all the passion of a dedicated slacker, there is no answer to
             your question, because there is no standardized spelling of "kattywampus," which is also often
             rendered as "cattywampus," "caddywompous" and "catawampus" (as the Oxford English
             Dictionary seems to prefer). As for pronunciation, if the choice is between "catty" and "katy"
             (as in the name "Katy"), I'd go with the short "a" of "catty" or "caddy." The "wampus" part
             seems to be most often pronounced "WAHM-puhs." 
             Since we're still on our extended coffee break, I'll take this opportunity to answer the question
             you folks didn't ask, namely what "catawampus" (as I'll spell it) actually means. Once again,
             however, the answer is not simple because the word actually has two quite distinct meanings.
             A "catawampus" can be a fierce, imaginary animal, the sort of vicious critter that jumps you in
             the woods shortly before you're never seen again. But "catawampus" can also mean "askew"
             or "out of whack," as in "Larry's elopement with Eloise knocked Cindy's wedding plans all
             catawampus." Neither meaning can be definitively traced, but "catawampus" in the
             eat-you-alive sense may well be a variant on the American folk term "catamount," short for
             "catamountain," or mountain lion. 
             The "askew" sense of "catawampus" is a real puzzler. The first element of the word, "cata,"
             may be related to "cater," also found in the related word "catercorner" (or, as many folks
             know it, "cattycorner" or "kittycorner"). "Cater" in these words comes from the French
             "quatre," or "four," and "catercornered" originally just meant "four-cornered." Today
             "catercorner" means that two things are diagonally across from each other. The "wampus"
             part may have come from the Scots word "wampish," meaning "to wriggle or twist," which
             would certainly seem to fit with "catawampus" meaning "askew" or "crooked."