Remember when mood rings were cool? Well, now you can be nostalgic in a more sophisticated way. Now you can wear your mood on your nails. Perfect Formulas created a top-secret polish that changes the shade from cool to warm, bright colors depending on your body heat. Doesn't that sound fun? The collection launches in June, but in the meantime, we found another way to have fun with nail polish.

Raise your hand if you enjoyed Mr. Sketch scented markers. How about scratch and sniff stickers? If you loved either of those in your youth, then perhaps the new Revlon Scents of Summer collection ($4.74, drugstore.com) will be right up your alley. The polishes have a faint scent when they dry. Don't sniff until the polish is completely dry though! Each polish is scented with a smell corresponding to its name (ocean breeze, peach smoothie, orange pop and gum drop).