- art and culture from the far future (flutes, 42 kya; figurative art, 40 kya)
- Simple ovens (29 kya) and pottery (20 kya)
- Rope and various ways to use rope (nets, clothes, bags) 26-28 kya
- Saws (20 kya)
- Dugout canoes (8 kya)
- Basic knowledge of health and disease (concept of potable/non-potable water, "fertility awareness" method for contraception, warm clothing, prevention of injuries, etc)
- Food preservation (salting and drying meat, fermented foods, perhaps sealing things with pitch?)
- Wheeled carts (3 kya)
- "Water bottles": animal skins sealed with pitch
Each of these can probably be made/demonstrated over a period of days or weeks and would likely impress the group. If I was really successful and managed to lead the group, I'd probably try to at least get us on our way to these things (would likely take generations):
- Attempt animal domestication (13 kya)
- Cultivation of barley and wheat (10 kya)
- Water wheel (2 kya)
- Migration to fertile region (Fertile Crescent perhaps?)