When Tyler went through the climbing phase (well, actually he is STILL in that phase) we let him climb up and down this little step stool/ladder that we have. However, he could ONLY use it when we were around to supervise. When we were not around, we put it away.
Sometimes, we would even let him push it around and climb up to play in one of the drawers in the kitchen. We just made sure all the sharp objects and anything dangerous was out of that drawer. Measuring cups, spoons etc could all stay.
I posted a picture of the stool/ladder. I think we bought it at Lowe's.
HTH.