Guitar Tuner
In this post about the Korg guitar tuner, the guy doesn’t mention that if you have an iPhone or other similar phones, there are aps for guitar tuning. I haven’t gotten it myself, but if you have an iPhone or one of the competing companies’ models, you might want to take a little trip over to the apps store before you buy anything.
That being said, I do like my Korg tuner. It’s sturdy (I can’t tell you how many times I’ve dropped heavy stuff on it and it keeps on going), simple, and accurate. Hard to ask much of a product beyond that.