Here are 5 of the most interesting i found, if you have more link to them in the comments!
Step 1: Mold Removal
Step 2: Invisible Ink
Take a q-tip and soak it in lemon juice. Use the Q-tip to write on the paper. Once the lemon juice is dry you can use heat from a lamp to reveal a secret message!
Step 3: Boost Laundry Detergent
Step 4: Blonde Highlights
Step 5: Electric Lemon
1. roll the lemon to get the juices
2. Cut 2 slits in the lemon
3. in one slit place a dime, the other use a penny.
4. Now you have electricity from a lemon, you can test how much with a multimeter.