I used a sheet of stainless steel from the hardware store (cost: $6) (Chicago store, The Crafty Beaver! yay!) and some Scrabble scrapbooking pages from the JoAnn's (around $1/each). I put self-adhesive magnet sheets (about $12 total) on the back of the letters and cut them out.
Then I just double-sided taped the "board" sheet to the stainless steel and arranged the letters underneath. Luckily there are way more than "regulation" boards give you, so you can spell out lots of long messages.
I drilled a couple of holes in the top and strung some picture hanging wire through them for easy adjustment to get it level.
Now my friend (Craftymed) can write messages (she loves the red headed men hence the message in faux Scrabble style "I Love Red Men")
or just play a game of scrabble on the wall. Didn't even break the bank!























