The oil drip pan was less than $10 at Walmart. It's 4' long, which ended up being a tad too big for our space, but having it hang over the window by an inch isn't really bothering me that much. I did three coats of the blackboard paint on the pan and am really pleased with the results. I also have tons of paint leftover, so I may do some sort of travel-board out of a cookie sheet. The Eskimo is currently in love with magnets. He loves to walk around the house, seeing what they will stick to. I've also ordered a bunch of really cute letter magnets off of eBay, which I think he will enjoy.
I stuck this to the wall with those Command damage-free picture hanging strips. The oil pan itself is quite light, so it seems like it's going to stick. I may have to come up with a stronger solution in the future, but for now, this is working. I can't wait for the Eskimo to wake up from his nap to see this! Now the trick will be getting him to draw on the blackboard and not every single other surface in our house.... Oh well, chalk washes off, right? ;)