How can I let fruit ripen faster?
As I was explaining in my answer to this question about figs the "brown bag" trick, works for any climacteric fruit.

A list of some climacteric and non-climacteric fruits can be found here.

It is important to note that some non-climacteric fruits (such as bell peppers or strawberries) will not respond to an ethylene treatment at all, and will not ripen further after being picked from the plant. Other fruits (such as citrus and grapes) will show ripening responses to ethylene, although they do not have an auto-catalytic production of this molecule1. 



1Ripening of citrus and other non-climacteric fruits: a role for ethylene