I call myself an advanced beginner. Some others call me an advanced intermediate. Still more others call me advanced.
Finally, there are those who call me foolish for attempting to quantify something I have fun with.
They are probably right.
But seriously, I looked through Brad Bordessa's list, as linked to by Gillian, and I have several traits from each of the categories (other than expert), but I'm missing a lot of them.
For example, I really don't give a damn about "strum patterns"; I strum or fingerpick as the mood and music strike me. I know a lot of chord patterns and positions, but not necessarily the names.
Because of some of the folks I occasionally play with, and their judicious use of capos, I have learned to transpose on the fly - sometime by ear, and sometimes by sheer luck.
I can't read music, tab confuses the hell out of me, time signatures are fine in the abstract, but don't expect me to count them out. I can occasionally remember the names of the strings, but not the names of the notes on the fretboard (although I still remember them from guitar, which I played 10 times longer than I've played a uke.)
But I can lead a song circle, easily have a 2-hour repertoire (unless you want me to remember all of the lyrics; then I have about a 1-hour repertoire), have played with people of all different skill levels (last summer, Stu Fuchs called on my to take a solo during a Jazz workshop with instruments running the gamut from ukes, guitars, and fiddles to woodwinds and brass. I surprised myself by making it sound good.), and have been asked to play at yet another Farmers' Market this summer, so I must be doing something right.
But I'm not coordinated enough to do a triple strum (a la Formby), nor can I play along with a metronome on anything other than simple rhythms.
Beginner? Intermediate? Advanced? How about I'm just "A Mess".
-Kurt