stay away from wet grass(slippy), wet drains, cobbles, looose gravel, sand, water
![Tongue :P](http://www.projumpforum.co.uk/Smileys/default/tongue.gif)
,
and yes you can use them on a hill, but you probably need some more experience for that, as it can be quite dangerous, depends really on what you plant ot do.
DC
P.S. you can use the Bocks on Pebbles at the beach... although when everyone is looking and you go running on to pebbles and fall over, its not fun
![Tongue :P](http://www.projumpforum.co.uk/Smileys/default/tongue.gif)