At the risk of sounding like a dork, here's something that I think is funny.  (Beware the "humor" of a linguist!) [:)]

"This book fills a much needed void..."

At first glance this statement seems to be a compliment, until the brain finishes parsing the sentence and realizes that it's actually an insult - a scathing one at that.  At best, the sentence dismisses the book as being unnecessary.  It implies that the book, by its mere existence, is a disservice to the world at large.  What is "much needed" in the sentence above is the void, not the book. 

That's why I think it's so funny that the expression "fill a much needed void" has come to be so commonly misused today.  An MSN search on "fills a much needed void" and its various forms ("filled a much needed void", "filling a much needed void", etc.) returns nearly two thousand matches, the vast majority of which misuses this expression.  Devices, books, academic disciplines, illegal aliens, the venerable Head Start program, and just about anything in the world that someone would find indispensible are all subjected to this insult by some of their most ardent fans:

• "The iTop is a very clever device and fills a much needed void in the vast iPod accessory market."
• "This is a great book that fills a much needed void in the psychological and legal literature."
• "The area of Clinical Rehabilitation Psychology fills a much needed void."
• "...illegal immigrants fill a much needed void in the labor pool (cheap labor)..."
• "...the Head Start programs fill a much-needed void for those who can’t afford typical childcare."

Even Microsoft products are fair game:

• "Microsoft has recently deprecated the Jet engine, so VistaDB appears to be poised to fill a much needed void."