Reason to Capo #1

To get out of bad keys like F, Bb, Eb, B etc.  A capo can make your life easier and make you sound better.

Dunlop 83 Trigger Curved Guitar Capo (Black) - curved for most guitars
Dunlop Trigger Classical Guitar Capo, Black Finish - flatter for nylon string guitars (this is why I was having problems in the video, I was using a classical guitar capo on a normal steel string guitar)
Shubb GC-20A Acoustic Guitar Capo in Nickel - My preferred capo for the studio
Kyser 6 String Capo, Black - my preferred capo for the stage
Shubb GC-20E Electric Guitar Capo in Nickel - my preference on the electric guitar

Some others to peruse...
Stainless Steel Deluxe Guitar Capo
Kyser Pro/Am Guitar Capo
G7th Performance Capo (Six String, Silver)
First Act MX220 Six String Guitar Capo
Planet Waves NS Capo, Silver
Jim Dunlop 7190 Russell Gtr Capo Reg - OLD SCHOOL!!!