There was a girl I knew from vaguely from college who once asked me what the Japanese character she had tatooed on her arm meant. "At the store they told me it means peace!" In combinations with other characters, yes, it can have that meaning. But sitting on its own on her arm it conjured up the rows of discount stores in Tokyo where the character screams "cheap! cheap!"
Engrish.com has been documenting the hilarious abuses to the English language committed in Japan for years, so I was extremely pleased to find the hanzismatter.com website in their links section which somewhat obsessively documents American mistakes in Chinese and Japanese character tatoos. While most of his entries are petty examples of upside-down characters and missed strokes (on the level of spelling mistakes), some of them are disturbingly funny. Ergo the marine who wanted "tank" on his arm and instead got "toilet bowl/feeding trough"(tank, get it?), or the unexplained tatoo of "shit/excrement" on one guy's thigh.
A few weeks ago I was out with a Japanese friend who had studied for a year in London, and she regaled me with the unbelievable names of Japanese restaurants out there. Apparently the largest Japanese restaurant chain in London is Wagamama (directly translated: "selfish"). Somewhat puzzling was "Moshi Moshi Sushi" (Hello Sushi), but the real corker was a Sukunai, which means "small (portions)".