Mehndi Skin Art Supply - several galleries, recipe, products
Art of Mehndi - several gallery/designs, recipe, info, tutorial (under constr), products, links
Henna Page - several galleries/designs, recipe, info, forum, links
Modern mystical adornment - several galleries/designs, recipe, products, links

Jane's Mehndi - gallery/designs, recipes, links!, gallery links
TapDancing Lizard - gallery/designs, recipe, info, links
MehndiFun - gallery/designs, recipe, tips
Helwa Henna - gallery, recipe, info, links, (popups)

Eve's Mehndi - several galleries, megalinks!
CCJ's free designs - lots of good free designs, good tips, symbol links
Tattoo-me - nice galleries/designs, recipe, products
Henna Hante - gallery, good recipe/info, symbols
Ananke Henna Art - galleries, info, products
Natural Expressions - gallery, recipe, info
Jenna Henna - gallery, recipes
Navel.com - design galleries (multi hands), cf Hunza.
Skinshock - gallery
HennaTattoo - body-art henna galleries
FlashLight - gallery/designs
Mehndi-Maddness - designs
Mehndi Designs - hand designs
Henna Caravan - gallery
Gilded Lily - gallery
Passage - gallery
St Louis Mehndi - recipe, info
BodyDeco - henna recipe, history, some products though UK
About.com - henna recipe, links
Relache - henna recipe, couple of designs
Ruchi - color vs time table
Cool angel-wings pic

Google search of the plant: Lawsonia inermis
Theatricum Botanicum - plant sales $7
Companion plants - plant sales w/ description $6
Richters - seed sales $1.25 (from canada) -under herbs, henna
How2GrowHenna - a few tips on growing the plant