mosriteforum.com

When you're practicing your guitar-playing behind your computer, like I often find myself doing -usually rehearsing with a backing track or working out chord progressions- and need to get in tune, check out this handy little tuner I found:
http://www.howtotuneaguitar.org/

Move your cursor over any one of the tuning buttons and click. Click once more on the same button to stop the sound or click on another button for a different note.
There's more but I'll leave it to you to discover and do some experimenting

Nice!