These startling before and after steroid suspension pictures of Shawne Merriman were just posted on Profootballtalk. The above picture was taken May 5, 2005; the bottom May 30, 2007. In 2005 and 2006 Merriman had 27 sacks in 27 games; in 2007 he has 5.5 sacks in 10 games.
Now sacks are a somewhat flukish statistic - a player's sack total can suffer even if he's still playing at the same level. But after watching the Chargers this year it's obvious Merriman isn't the same disruptive force he was the last two seasons. It's also obvious his neck is half as big.