I'm currently enjoying a 30 day free trial to the Wall Street Journal Online, which saved me $1.50 in the airport last weekend when I saw a headline about how "fresh" your sushi really is. Instead of blatantly violating copyright by pasting the entire article text below, I'll share a few tips...
NEVER ON SUNDAY: Most restaurants do not receive fresh fish on the weekend, so it is certain to be less fresh than on other days. In some places, Monday is even worse.
NEATNESS COUNTS: Look in the sushi case at the bar. If pieces aren't wrapped and are touching one another or the sides of the case, says Sushi Sasabune chef Nobi Kusuhara, "they aren't really taking care of the fish very well."
EXPECT VARIETY: Offerings that change according to the season usually mean the chef takes pride in his selections.
GOOD LOOKS: Fresh fish will look shiny. Tuna should not be dark or too red. "When the color is red, almost as if it's been painted, ask if it has been smoked," says Mr. Kusuhara. If so, "it won't taste good and could be spoiled inside."
FOLLOW THE CROWDS: Unpopular restaurants may not have enough turnover to have fresh fish.
SAY NO TO SPICY SUSHI ROLLS: The spices are often intended to disguise inferior fish.

Too bad we broke rules #1 and 6 last
weekend.