I use the clip-on type chromatic tuners too. have too, i don't trust my ears.
I've tried doing it by ear using sites like the one in the above link. I've tried other sound methods too, like tone generators, tuning forks, a electric keyboard, my own professionally tuned piano, aldrine's tuning video... but even when i think i got it right on the individual strings, when i start playing i can sense that something is off... just a general feeling tho... a chromatic tuner will verify my feeling. it's sad really. i've got buddies that must have perfect pitch and can pretty much tune each string by ear without any thing as reference... me, jealous.
the clip on chromatic ones are a godsend for me... and i've got all types... some are better than others. the one they sell here at the UU store is one of the better ones in terms of functionality (has a mic too) and quality... it's a little on the big side tho. you might not want to keep it clipped to a small light soprano or even smaller fractional sized uke.
