(I'm going to preface this by saying my Chinese may be a bit rusty, and my the extent of my Japanese is about 20 words)
@ScotInExile your one unfortunately isn't a character in either Chinese or Japanese at all, I think, because the placement of each stroke doesn't follow logical character construction. Unless it's one of those new-fangled Internet words I keep hearing about.
@OwlBeThere your character is too faded to tell, but also unfortunately doesn't look likely to have been a real character at any point.
@Frustratedandworried your one is a transliteration of Danielle into Mandarin, but what makes it funny is that because Chinese doesn't have a phonetic alphabet, the transliteration of each syllable is always into a character that mean something in itself. So your tattoo, read by someone with no knowledge of English, reads as "day, nun, oh".
@MyNameHasBeenTaken your one is really interesting. Individually, each character exists. Taken together, though, I have no idea what it means. I showed a pic to my mother (who studied Chinese literature in China), and she says it vaguely sounds like the name of a company 
she did only look at it for a second, though. I would love to know what it's supposed to mean!
@IItCantRainAllTheTime your character says "son", and has nice handwriting!