As weeds go you can do a lot worse than Hairy Bittercress, which is just as well as it's currently taking over one of my uncovered vegetable beds (it's giving my soil protection from the winter weather).
This is an annual to biennial weed - seedlings can withstand the severest frost, making it a very hardy weed. It carries hundreds of explosive seed pods that when ripe, can explode suddenly in all directions up to a metre around you (so weed in glasses!). The seeds generally germinate between April to December.
Hairy Bittercress is easy to remove from the soil with a hoe or by hand and it's important to do so as it can quickly smother beds containing your small vegetable seedlings, competing with them for space and light. Once removed the weeds can then be added to the compost heap.
If you don't mind eating *weeds however, Hairy Bittercress is edible, apparently tasting of watercress. I promise to give it a go when it stops raining ;)... Have you tried eating it?
The following is an audio clip of my tasting session. Apologies for the slight mad excitement of being out in the fresh air again, am new to audio!
* A weed is just a plant that's growing somewhere that it's unwanted.