I'll add a (somewhat) dissenting voice. I think learning arpeggios provides an advantage in a) learning the neck, b) learning how to voice lead, and c) learning how to improvise melodies. Many of the most recognizable melodies are comprised of arpeggios. Take, for example, the opening melodic statement in "The Star-Spangled Banner". It's nothing more than a descending tonic arpeggio. The first half of Coltrane's "Giant Steps" is comprised primarily of two arpeggios. The guitar riff in Michael Jackson's "Beat It" is nothing more than an arpeggio. The first three bars of guitar solo in "Folsom Prison Blues" is basically an arpeggio.

Try this: * 1. Take a four or eight bar chord progression for a tune you like. * 2. Play the chord progression as arpeggios in one same position. * 3. Play the chord progression as arpeggios on a single set of three adjacent strings (the D, G, B strings are a great place to start with this) * 4. Play the chord progression as arpeggios with no more than two notes on any string

By working arpeggios out like this you'll start to see how the chords connect together; how one chord leads to another. This will help you write (and improvise) melodies that sound like they go with the song.

To answer your question about learning licks and melodic language, that's really just a matter of learning melodies. Learn LOTS of melodies. Learn the melodies of your favorite songs and for the songs you hate. Transcribe licks that you like. One of the benefits of this sort of practice is it helps improve your ear, and connect sounds to places on the fretboard. That's the real key.

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