Ah...calamansi! My fave citrus fruit from the Philippines!
Growing up (and even now when I have the opportunity) I like taking fresh calamansi, slicing them in half and throwing a few in my glass of water with some sugar. At my house this is what mom called "lemonade from the islands." Ah....childhood.
LAZ is correct in describing the taste as a cross between a lime and mandarin oranges...sweet, tart and a little sour. I have spotted frozen concentrated calamansi juice at a few of the UniMarts grocery stores awhile back - not sure if they still carry it.
The Calamansi Maggi sauce has been around awhile, at least I remember spotting that while vacationing in the Philippines for 2 months last year. There are other asian sauces/condiments that have calamansi influence, such as:
Patismansi - Fish sauce (patis) + calamansi
http://www.georgiaharvest.com/images/ca ... ZZZZZ_.jpg
Toyomansi - Soy sauce (Toyo) + calamansi
http://www.pinoyshop.nl/shop/home_7_4.JPG