What alternatives do exists for properly squeezing lemons? This happened to me often when I go to some restaurants or be on a visit to somebody place. It just happen that I want to add some lemon to my soup or use it as an addition to my meals but they do not have access to a lemon crusher. Is that the name of the tool?. 

I've seen people used forks, spoons and just their thumb for squeezing the juice of the lemon. But is there a method which has proven to work the best to take out all of the juice without trying to make much force with the hands or something?. Is there a tool that can be carried on maybe portable for this purposes?.
A lemon wedge squeezer may be what you want.
They are 
and the lemon wedge .

(Pictures from Amazon.com)