using a lil salt with anything sweet works - the chemistry is something to do with extra ions(from the salt) aiding transfer across the receptors in the tongue so giving more flavour. it's real usefulness comes from being able to reduce the amount of sugar you use in almost anything by adding a tiny amount of salt
I always have black pepper both on strawberrys and fresh pineapple, but I have never tried salt. Banana sandwiches always benefit from Brown sauce.
Incidently, I am always getting teased at work for washing my fruit with soap - usually washing up liquid, but I do use the hand soap at work. I don't think that water alone gets the horrible coating and other peoples greasy hand debris off. I always rinse them properly and they never taste soapy, but apparantly I am weird and some people don't bother to wash them at all.
A girl I used to work with put salt on her apples! I thought it was an Asian thing coz she was the first person I saw doing it and I had never heard of it before. You are the second - very strange!!
Make a fruit salad with spices its great.
Just chop up a selection of favourite fruit, add salt, pepper, lemon juice and if you like sugar. You can also add other spices too like ground mango powder, tamarind, red chilly.
Salt and black pepper on melon is great too (not watermelon), and on guava.