hehe... he's using the EXACT same thing m8
The only difference is that the Boris tut also explains a random rotation expression, and a collision event expression.
FYI: lots of expressions can be found here as well:
Good find, so it is up to you. Same technique, different execution.
Have fun, and lets see it when you are done ok?
Israel "Izzy" Long
Motion and Title Design for Broadcast-Film-DS