Legato [ ptb | mp3 | mpg ]
Legato is smooth playing where barely any picking is utilized.  In this lick, we are going down G Ionian.  To work on this riff, first take part the first 2 triplets.  Once you got that down, the rest is basically the same riff, just different notes as it has to apply to a scale.

G Major Legato[ ptb | mp3 | avi ]
This riff is in G major and ascends through all the modes.  You basically hammer-on all the notes except for the first note of each string.  That note is picked.