Pictures of various types of paper clips: 

Binder Clips
Bulldog Clips
Regal Clips
Gold Paper Clips
Binder Clips
Bulldog Clips
Regal Clips
Stockwell Gold Paper Clips
Acco Paper Clips
Belt Clip
Color Paper Clips
Paper Clamp
Acco Paper Clips
Belt Clip
Color Paper Clips
Paper Clamp
Banker Clip
Magnetic Clips
Memo Paper Clip

Banker Clip
Magnetic Clips
Memo Paper Clip

These pictures were taken from the staples web site and form the web site of researcher Jenn Harvey http://fresgisvr.frostburg.edu/class/sp00/engr/engr03/