(MONEY Magazine) – -- Dinosaur dig (406-994-2251). Spend a week at Egg Mountain near Choteau, Mont., searching for dinosaur fossils with paleontologists from the Museum of the Rockies. You sleep in Blackfeet tepees and cook outdoors. Adults: $900; kids 10 to 17: $700.

-- Grand Generations (312-929-7200). This 11-month-old company offers tours for grandparents and their grandkids. Tailored for children eight to 17, a 10- day Alaskan cruise embarks from Vancouver on Aug. 12, with stopovers in Ketchikan and Juneau. Standard cabins for two run $3,199 per person; a third or fourth person sharing the same cabin pays $2,399.

-- Caretta Research Project (912-355-6705). Summer volunteers can participate in a conservation program at the Wassaw National Wildlife Refuge near Savannah, performing such services as tagging loggerhead sea turtles on the beach. Lodging is rustic (eight bunks to a cabin), and everyone shares cleanup and cooking chores. Weeklong stays from May 15 to Aug. 14 cost $395 per person and are reduced to $350 from Aug. 14 to Sept. 18. All meals are included. Minimum age is 15.