Step 1 Find that 3-D chalk drawing guy and a well paved sidewalk.
Step 2 Have him draw banana peels all over, about 5 meters down the walk.
Step 3 Then place the real ones down just like he draws them.
Step 4 Try it out first. This one might be deadly if it works.
Step 5 Challenge your friend to a race that crosses the path they think is chalk.
Warning: friend prank only! Civilians walking to work in suits and ties would most likely be angry if they get hurt and soil their attire.
p.s. You all are a bunch of jackasses making people feel like jackasses