The kaneda bike you unlock from the ronin missions will drive all the way up the side
of any building. You need to face the wall and then backup far enough so when you go 
forward you can wheelie and have your front tire rest on the wall. Then give it gas. 
If you just do a wheelie at the wall it wont work, you will just do a big burnout on 
the ground. You need to get the timing right so you are just far enough away to be 
barely doing a wheelie when you hit the wall with the front tire.