You can use this technique to play chords or scales.
The idea is to play one note per string.
Then let your pick "fall" from string to string.
You have to mute the note played right away, using your fretting hand.
When playing upwards; just drag your pick upwards over the strings.

Sweep picking.
To start off, try this technique using a pentatonic box.


Sweep arpeggios.
Play a "C major chord" one octave higher.

e------------------------12------------
B-------------------13--------------------
G--------------12-------------------------
D----------14---------------------------
A-----15-------------------------------
E-------------------------------------
fing.....4......3....1.....2.....1