A few years back I started sitting in with some folks at open bluegrass jams.  One thing I noticed right off was that everyone had a clip on electronic tuner and a capo.  Most of them had the Kyser.  I got one and its been great!  I recently got another one.  They come in several different colors.  I primarily use them on acoustic.  You can also use it as an extra hand if you do set up work on your guitars.