Oh boy. That was such a tough age!!!! They're becoming mobile, which means they just want to get into trouble 24 hours a day! But they are too young to reason with, so you can't really tell them 'no' and have it mean anything!
That's the age we starting having 'discovery baskets'. I'd just put a lot of different things into a basket/bucket and let Owen go through them and examine them to his heart's content. The best items are things from nature (pine cones, rocks -big enough not to be choking hazards-, leaves) and things from around the house that he sees mommy and daddy using (measuring cups, measuring spoons, plastic containers, things he can bang together, filling a old pill bottle with rice for a rattle, etc.). The discovery basket would keep him busy for awhile because it seemed like it was naughty!
I also just baby-proofed my rooms enough that he could wander around to his heart's content without getting into trouble. He loved going through our CDs, so I gave him a bunch of empty CD cases to bang around with. I put his toys at his level, so that he could just get into them. I think this age is about the time we introduced blocks. He obviously couldn't stack them or anything, but he loved holding them and trying to manipulate them. A shape sorter is great for the same reason -- there's no way then sort the shapes, but they love feeling the shapes and putting them in their mouth. Good cloth story books that they can't rip are nice too because they can mouth them and try to turn pages without hurting them.
It's best to make the house safe enough that they can wander to their heart's content. The only thing that will satisfy will be wandering, so it's best not to fight the instinct and let them have a go! When Owen learned to crawl, we were also living in a very small space. I actually found that a good thing because he couldn't get into too much trouble without me knowing about it. Oh! And an exersaucer is a great toy for this age. It keeps them occupied in a place where you know they are!
