A Blues Scale

This is a very common blues scale, and a handy little one to know. 
Not only does it sound cool, but many songs are also based off of it.

Heres the general pattern:

G———————————0—2—
D—————0—1—2—————
A—0—3———————————
E———————————————

The real magic happens when you play it backwards:

G—2—0———————————
D—————2—1—0—————
A———————————3—0—
E———————————————

Sounds pretty bluesy, eh? You can play this same combination 
of notes anywhere on the fretboard. For example, here it is further 
down:

G———————————————
D———————————5—6—
A—————5—6—7—————
E—5—8———————————

That above combination will produce the same sound as the general 
pattern above, but you can play this same pattern anywhere to 
produce almost any pitch you want.

Now, heres the important part: the blues scale in popular music. 
There are many songs that utilize this blues scale; most of which 
date around mid— to late—60s, but its used in some popular music 
today. Here are some examples of famous riffs that use this blues 
scale:

Heartbreaker (Led Zeppelin):

G—————————————
D—————0—1h2———
A—0—3—————————
E———————————3—

Sunshine of Your Love (Cream):

G—2—2—0—2—————————————
D—————————2—1—0———————
A———————————————0—3—0—
E—————————————————————

(Note: the above examples may not be the actual notes used in 
the song, but are rather examples of the blues pattern in popular 
music, shown through the incarnation of the blues pattern that 
I tabbed above.)