i wouldn't adopt it TBH as it was not imprinted on you so may be quite aggressive and could do a lot of damage. corvids are some of the smartest birds in the world and easily learn tricks. a main diet would be things like defrosted chicks and stuff like that. i may be getting a magpie next breeding season as i know someone who gets lots nesting in his area and shoots them because of their baby bird eating tendencies..

(its how they survive... you eat more than they do... it ain't fair to kill em!) and often finds their nests with the orphaned chicks that have died or cold eggs... so i asked if i could come and have a look around to see if i could find any baby ones to take (so of course he thinks they are destined for the inside of a snake so he doesnt mind).
so my plan is to get a newly hatched one or an about to hatch egg and imprint on it and when its ready to fledge begin to fly it outside. after it has learnt to fly it can stay outside and i will feed it. lots of people have done this before, usually with magpies and crows that have fallen from the nest and it seems they always return to the person who reared them and follow them around...
even if it doesnt work its better than death!
http://www.falconryforum.co.uk/showthread.php?t=30716&highlight=ravens this is a person who keeps ravens and teaches them tricks and stuff (which can be seen on page 9 second post from the bottom and some other parts that i couldnt find) this is a falconry forum so it isnt very corvid friendly usually as most Birds of prey love a juicy bit of crow now and again... but this post is quite interesting.