Some great deals that will appeal to families.
Lakeside Amusement Park: Great fun for kids of many ages! Here is a deal from Groupon for 50% off admission [which is not cheap, so this makes it plausible for a family to go].
Twirl Frozen Yogurt in Boulder is offering a BOCO Deal: $20 of yogurt for $10.
Boulder Baked (Cookies): 16 cookies plus a quart of milk for $8. Yum! Groupon deal.
Diapers.com discounts: $10 off a case of diapers (code: ohbaby10d) or 10% off almost everything else (code: ohbaby10p)