Note: I am also using an improvised mattress made out of eight $9 sleeping bags inserted into a zippered vinyl mattress cover to go with this DIY platform bed for a complete, inexpensive, portable, lightweight bedding solution. Details are at https://www.instructables.com/id/DIY-Mattress-Substitute-Portable-Inexpensive-L/
Step 1: Buy 12 "LACK" Side Tables From IKEA
For a queen bed, buy 12 "LACK" side tables from IKEA - http://www.ikea.com/us/en/catalog/products/20011413 ($7.99 each as of 05/26/10). Each individual piece weighs just 10 lbs and measures (as packaged) 22" W x 2.125" H x 33.125" L. Though made of particleboard and therefore extremely light, I was told each table can support the weight of one adult standing on it. I was able to load and fit all twelve packages into my subcompact car quite easily.
Step 2: Assemble Each Side Table
Assemble each of the 12 tables for the queen bed by attaching the four legs to the table top with the help of the four screws supplied. The screw is pointed at both ends and there are markings on the underside of the table top and each leg showing where each screw goes in. You don't even need a screw driver as the leg itself acts as one. Assembling each table took me less than 15 minutes.
Step 3: Arrange the Side Tables Side-By-Side
Arrange the twelve tables side-by-side - three on one side, four on the other Each table is 21.625" x 21.625" so the final dimension of your platform bed will be 86.5" x 64.875" - which is slightly bigger than a standard queen size mattress of 80" x 60" but once the bed sheets and covers are on the mattress, I haven't found it to be a problem.
I thought I might need to duct tape or otherwise tie the legs together but haven't needed to do it - the tables are totally staying in place on their own.
That's it - you now have your off-the-shelf platform bed for around $100 that you can take apart, move (even up and down flights of stairs) and put back together all by yourself at any time - no messing around with tape measures, hacksaws, drills, clamps and hammers in the garage for hours on end, no sweat and grime at all.
P.S.: I am also using an improvised mattress made out of eight $9 sleeping bags inserted into a zippered mattress cover to go with this DIY platform bed for a complete, inexpensive, portable, lightweight bedding solution. Details are at https://www.instructables.com/id/DIY-Mattress-Substitute-Portable-Inexpensive-L/
MikeD106 made it!