Virtual Guitar, Scales Finder & Tuner from chordbook.com

chordbook.com has various useful tools for guitarists. They are -

Virtual Guitar & Chordbook 

This features a flash modelled guitar and chordbook with over 1300 guitar chords and inversions. See and hear the chords you select.

http://www.chordbook.com/guitarchords.php

Guitar Scales Finder 

Choose from a list of scales, load them onto the guitar and practice along.

http://www.chordbook.com/guitarscales.php

Guitar Tuner

checkout standard and alternative tunings 

http://www.chordbook.com/guitartuner.php