Yes its possible. I am doing it as we speak (you can check out the 2011 Grow Journal thread). I have a Larry OG that I put outdoor, it was in a rockwool cube and was kept under 24 hours light at the dispensary. Therefore...when I put it out, it started flowering on me. Now I am hoping it revegges no problem and grows into the fall.
So listen to Hemp Goddess and harden them girls off good(if its possible

) before putting them out. I was told that the day to put clones out in my neck of the woods is June 1. I want to b greedy and go get one tomorrow and try to get a head start...But I will of course be running the chance of it flowering on me and then having to re-veg...OBVIOUSLY it is not recommended for it to reveg because its sever stress to the plant...However I was told by a vendor who that sometimes re-vegging can be beneficial; i.e. when the plant re-vegges and then continuous to grow vigorously on top of its "already in place structure".
** On that note(sorry to take it off topic but its a must), has anyone seen some video I saw on youtube of plants in Northern California that are literally TREES!!!!! They are huge, sizes of trees...I was pointed to this by this vendor and he said that some of those plants/trees produce year round???