Today's side deal introduces your kid and his or her friends to the joys of science: for $85, you get a 45-minute interactive science-experiment birthday party for up to 15 kids ages 4–12 from Mad Science (a $165 value). Your Groupon also includes a goody bag with polymer putty, helix flyers, stickers, and more for the birthday kid (others may be purchased for an additional fee of $4.95/bag). Mad Science's Orange County services will come to you, but this deal does not include the travel fees (starting at $25, check the sidebar on the right for service location information).

Kids will have so much fun launching spinning disks, applying temporary tattoos, mixing their own silly putty, practicing maniacal laughter, and reanimating dead tissue that they'll forget they're learning. The eight to 10 interactive experiments rarely make a mess, and Mad Science will handle any wacky hassle or silly spill. Upgrades are available by applying the value of the Groupon and paying the additional charges.

Two Groupons may be combined for a 90-minute Mad Science session.