Oldschool Tag
OKC
Ornamental Initial
Oto Tanpa + Choucha
Orthogon
Oblaque Oblique
Origami Mommy Pixellated
Overheads
ORU
Orgasmo
October Guard Platinum Italic
Oh Mighty Isis Rotated
o-wee-ental
One Smear
Osaka-Sans Serif
Oyget!
Organo (colored version at: logomagazin.com/organo-font)
Ormont
OrganDonorSkin
Old Dog, New Tricks