With a new little fulltimer in the FT (4 total people now), we needed a new sleeping arrangement. Not much room for a giant bedside bassinet in a foretravel! We also have two cats, and didn't want to leave a crib in the living area for fear of too much snuggling up next to the smell of milk.
Originally when we moved into the FT full time, our other son was 14 months old, and this was the old solution:
Brainstorming Help - Adding Crib/Child Bed to Master Bedroom (http://www.foreforums.com/index.php?topic=29615.msg252469#msg252469)
But he's now a healthy 2+ years old and 30 pounds, and that setup didn't contain him anymore. He's been sleeping in the bed with us for a few months.
Our solution? The wall-to-wall bed.
Pretty much just a cut up piece of "cabinet grade" 3/4" AC plywood, secured to the bedside tables, some A-braces and corner brackets, two 2x4 legs underneath, some peel&stick tile, and a ton of sandpaper. We lose the bedside drawers, but will just grab some temporary storage bins, put them underneath the sidebeds - so what we really lose is the ability to climb out the side of the bed! They are sturdy enough for an adult, so no need to climb in and out gingerly. 16 screws and can be removed and carried out in one piece for when they are outgrown. The toddler's foot-of-the-bed is much higher - he tends to "crawl up" at night, and didn't want him taking a leap off the bed if he got turned around.
Pardon the unmade bed and the lack of sheets on one mattress - I jumped the gun when I was finished to show the wife.
There is a video about a family with five kids who built bunk beds on each side of the original bed and replaced the original mattress with a pad (play area). You could build two bunk beds on one side of the bed and still be able to use the other side as original.
Here it is:
Tour of our 95 U300SE, Including bunk room remodel! (http://www.foreforums.com/index.php?topic=32328.0)