Tricks with Open G

[ZoSo0789]

Can anyone tell me a few tips and tricks when using Open tunings? Right now I'm messing around with Open G (DGDBGD) in particular. Stuff like.....
- soloing tricks with slides (what frets and strings can make a cool finger picking melodic solo)
- Fingerings to use to make different kinds of chords (more bluesy stuff like 7ths) instead of just barre chords for the standard note
- anything bluesy
-anything stylistic-wise like..... Duane Allman, George Thorogood, Hubert Sumlin, Robert Johnson, and even Keith Richards I guess
- what frets to do some cool walk downs on the turn around chord ala delta blues style

anything to help me expand would be cool

[ZoSo0789]

this is a cool rendition of Crossroads..... it'd be cool to learn how to play stuff like this in Open Tunings.
http://www.youtube.com/watch?v=6injpgY_I2U

Whats those fingerings (besides the barre with his index) he's using for the rhythm chords?