This picture shows what stinging nettle looks like in bloom.
Sure, it's not much of a bloom -- I grant you that. There's no way it's going to make any of my galleries showing photos of colorful flowers. You probably won't be growing stinging nettle in your garden any time soon (on purpose), overwhelmed by its good looks. People interested in planting herbs may grow it in their gardens -- but for medicinal and culinary purposes, not because it's attractive!
Brush up against the barbs of stinging nettle (Urtica dioica) and you'll soon feel a burning sensation. This weed causes a skin rash on contact. The severity of the rash may vary from person to person. I would categorize the results of my own brushes with stinging nettle as more of a nuisance than anything (although the discomfort can be rather severe, at first).
Incidentally, as Cathy Wong, About.com Guide to Alternative Medicine, warns, even when taking stinging nettle as an herbal medicine, you have to be mindful of its potential (as a side effect) to cause a rash.
On the culinary side of the ledger, Molly Watson, About.com Guide to Local Foods, offers a recipe for making a stinging nettle soup. Personally, I have experience only with eating stinging nettle (when the leaves are young and tender) as a boiled green, the way one would eat spinach.