For a fascinating history and overview of the common paperclip see A137620

Key:

b = broken/snapped

c = large number linked to form a chain or chains

e = (fully) extended form

f = folded form (as manufactured)

l = small numbers linked together

p = partialy extended form

r = refolded form

t = twisted form

* = warning: potentially controversial

In no particular order:

1. A tool for removing stones from horses hooves ¹ -p
2. Repairing ones glasses ² -brt
3. Hook for hanging wet clothes in the hotel bathroom/window/balcony when on holiday -r
4. Stiring liquids such as coffee or paint ³ -pr
5. Tool for preparing the Banana in the Amazing Unpealed Banana Slicing Trick -ep
6. Picking a lock -p*
7. Lowering mechanism for escaping from a fire via a window ⁴ -c
8. Implement for bursting a helium balloon when it's tied to your friend's/child's wrist and they're being dragged along by a strong wind -e
9. Implement for removing shell fish from their shells -p
10. Newly weds noise-making car adournment -c
11. Gentleman's watch chain -cl
12. Musical instrument (percussion) -cl
13. Makeshift holepunch -p
14. Splint for injured finger or leg of small animal -er
15. Spragwort ⁵ at base of rain water collection device such as plastic sheeting -fprt
16. Replacement for belt pulled across closed supermarket checkout lane -c
17. Extracting insects, worms and other foodstuffs from crevices during survival training, real life emergencies or when otherwise hungry -ep
18. Shoe fastener -r
19. Material for making collages ⁶ -fr
20. Etching tool in art class -p
21. Removing skin from the surface of milk drinks or paint ⁷ -p
22. Creating an air hole for fish in a frozen pond surface -ep
23. Substitute fish hook -r
24. Replacement/repair to broken clasp or box closure mechanism -tr
25. Temporary replacement for lost padlock (note: non-secure solution) -tr
26. Replacement axle in toy car -b
27. Replacement lavatory flush chain -c
28. Pet rodent footbridge -c
29. Item of equipment in a magnetism experiment -ceflprt
30. Punk accessory (safetypin substitute) -ceflprt
31. Pierced nose/ear/body part ornament -ceflprt*
32. Piercing the straw hole in a drinks carton when the straw is missing or blunt -p
33. Intruder tripping device -c*
34. Intruder detection device -efpr
35. Cleaning conglomerated dirt and fluff from the rollers inside a computer mouse -pr
36. Removing lids from containers such as tins of paint -fp
37. DIY tattoo tool (with ink) -p*
38. DIY body piercing tool -p*
39. Button substitute/replacement -frt
40. Removing torn scraps of paper from the inside of printers and photocopiers ⁸, ⁹ -pr*
41. Bird Scarer -c
42. Emergency surgical impliment -pr*
43. Removing dirt from underneath finger nails, toe nails and other body crevices -epr
44. Replacing a lost or broken zip puller -fr
45. Opening the silver paper seal on a milk carton when the tab has come off -p
46. Etching your/your partners name to the bark of a tree or other wooden object -p*
47. Bookmark -ceflpr
48. Replacing a broken link in a necklace/pendant chain -fr
49. Lengthening a necklace/pendant chain -cflr
50. A necklace/pendant chain or bracelet substitute -cr
51. Retrieving a small, dropped object that has rolled underneath an item of furniture -ep