Chad Dickerson - The top 20 IT mistakes to avoid:

"18. Underestimating PHP

IT managers who look only as far as J2EE and .Net when developing scalable Web apps are making a mistake by not taking a second look at scripting languages -- particularly PHP. This scripting language has been around for a decade now, and millions of Yahoo pages are served by PHP each day. [...]

19. Violating the KISS principle

Doug Pierce, technical architect at Datavantage, says that violating the KISS (keep it simple, stupid) principle is a systemic problem for IT. Pierce says he has seen “hundreds of millions” of dollars wasted on implementing, failing to implement, or supporting solutions that are too complex for the problem at hand. According to Pierce, although complex technologies such as CORBA and EJB are right for some organizations, many of the organizations using such technologies are introducing unnecessary complexity.

This violation of the KISS principle directly contributes to many instances of project failures, high IT costs, unmaintainable systems, and bloated, low-quality, or insecure software."