There's a commentary that goes with this one, but you can still have the word first.
上手 (jouzu) adj,n. - skill; skillful; dexterity
Used to comment on someone's ability at doing something, as in 日本語が上手ですね (Nihongo ga jouzu desu ne), or "You're good at speaking Japanese." A common rejoinder to such a compliment would be, いいえ まだまだです (Iie, madamada desu), or "No, I still have a long way to go." (See how I worked in that old word of the week in there? Heheh...) The opposite of jouzu is heta (下手), used in exactly the same way, just meaning unskilled instead of skillful.
Therein, of course, lies the story. I certainly do have a long way to go, and as nice as it would be to be fluent in the language, as Andrea put it, I'm not there yet. If I had to put a grade level on it, I could probably function at about a 3rd grade level of Japanese, in a pinch... and that might be overestimating it. (I don't know exactly how it works out, after all... it's not like there's an easy-to-find test laying around that I can take for such things. At least, not that I know of.)