Clare (3BT) Grant posted these on the original version of this blog, I didn't want to lose them
1. Swap seeds for those of 60 different plants.
2. Write 60 beautiful things. 
3. Write 60 haiku.
4. Learn 60 words of a language. 
5. Fold 60 origami dragons (google for a simple one), write an inspiring quote and your blog address on each and leave in a public place for someone to pick up. See http://www.1000cranemission.com/ 
6. Eat 60 different kinds of sushi (not in the same meal!) 
7. Find 60 geocaches.
Also: postcrossing.com and bookcrossing.com -- you could send 60 postcards, and give away 60 books you no longer need.

I wrote 50 memories about each of my schools at http://bclaregrant.blogspot.com/search/label/50%20things -- perhaps you could dredge up 60. Or 60 memories of Nepal, or travelling generally. You've probably got some pictures to go with them, I expect.

You might also get some ideas from 43things.com