Robert X. Cringely wrote an interesting article today called The Truth About IT Consultants: Some are great but most are not. If you deal with IT consultants, it's a worthwhile read.
Here's a sobering statistic from the article: "...more than 50 percent of big IT projects fail completely...". Why? According to Bob, projects sometimes fail at the requirements phase, a company may be incapable of setting their own requirements. Projects may also be "too grand" and Bob warns that companies may not realize they've bitten off too much until it is too late.
Certainly anyone involved in IT will get a chuckle out of Bob's 10 most frequent lies told by IT consultants. My favorite: "Of course your data is safe".