I love these clip-on tuners. They are so much more accurate than the others. Accuracy equals less time tuning. Plus they are affordable.

I have a Korg PC-1 chromatic clip-on.
http://www.guitarcenter.com/Korg-PC1-Pitchclip-Clip-on-Chromatic-Tuner-106904774-i1934340.gc

Got it at Guitar Center for $20. Amazon has them for $13. It has a left handed feature so as a lefty, I don't have to read it upside down. It also turns itself off automatically if you forget.