My DS started crawling a little bit yesterday! strangely our situation is the opposite of yours... thinking he needed less bulk to get around better I now have him in non waterproof training pants most of the time we're home. I have moved the potty into the living room and made a little "potty corner" with clean trainers,clean-up rags, waterproof changing mat and potty. (I got the idea from Montessori method of PT--eventually he will explore that area and play with the cloth trainers, practice getting on and off the potty himself, etc. For the time being he takes great interest in the little spot of pee that leaks onto the carpet and watches me clean it up.)
So with more diaper free time (ie in trainers which still catches the brunt of the uh-oh) we're getting more hits.. which is still far from perfect! As for poops I take him to the toilet and hold him when I know that is coming... so he can't get away. We have 2 toilets and when I suspect he is getting bored with the main one I take him to the guest toilet, use a sink or bathtub, I suppose if he hated all those locations I would find somewhere new!
From what I've heard the time span from crawling to walking is pretty bad for a lot of ECers... I figure the main strategies for me would be not to sweat the accidents nor turn it into a power struggle... and use the level of back-up that you need to protect your house and lap... :)