Build a chicken run?

How secure?

Dog kennel and a dog house works well.

Deer netting around some old posts with a staple gun if you need ultra quick. For housing you could use anything from a 5gal bucket cut in half to an extremely sturdy cardboard box... The kind the ship produce in and you turn it over. 

Like this one;

http://farm7.staticflickr.com/6220/6283864579_df6533b709_z.jpg

But these things aren't very weather proof or predator proof. It takes a lot more work to make it predator proof. Like digging.

Oh! What you want is called a Chicken Tractor! 8D

http://thecitychicken.com/tractor32.jpg

This is an A-frame chicken tractor and it probably the most common.

They come in a lot of different styles but the idea is it's just hardware cloth on a frame that has a small shelter and easy to carry/move.

Here is another design;

http://www.bellhavenfarms.com/projects/chicken_tractor.html

Run a search here and on google for chicken tractor and you'll find TONS of info!

How about something like this?  I made it to keep the chickens out of my veggie garden.  It only has chicken wire and I am using a tarp over the top.  I added a small shelter on the end for hiding in, but they don't seem interested in using it.  Basically, it is a frame with wheels and chicken wire.  This picture was taken before we got the all of the chicken wire on, but you can get the idea.  It's 8 ft by 10 ft. with a small access door on one side.

I saw this on BYC a while ago and it looks easy to do.   Jaxon4141 posted their pictures of their hoop coop on this thread:  http://www.backyardchickens.com/t/646663/hoop-run

I'm thinking of doing something like this if I decide to get into meat birds.

Good Luck