For anything sticky use rubbing alcohol to remove it - it is most useful for removing stickers and UPC tags. Don't spend hours trying to scrape it off, just use rubbing alcohol. It's a great solvent.
Also, use rubbing alcohol to clean your electronics. It won't harm your gear as it evaporates quickly. It's great for dirty CDs or DVDs, but also for flat screens and for soaking really gunky equipment. It's great at cutting through oil. Use it on your iPhone screen!
Wikipedia has some other great uses: http://en.wikipedia.org/wiki/Isopropyl_alcohol
And I always throw this one out there - hydrogen peroxide is great for getting out blood stains (but may discolor fabric - do a test first).
Bonus: Keep acetone fingernail polish remover around if you're playing with super glue. It'll get it off your skin instantly.
Tell all your friends!