Using agar agar as a substitute for gelatine - help!

URGENT!

I am doing a favourite recipe for a vegetarian guest. It usually includes 12 grams of gelatine  to set 625 g of pureed strawberries, 3 oz sugar and 300ml of low-fat creme fraiche. This is poured on either a thin no-fat sponge base or fattening choc biscuit crumb base.

My question is, does anybody know how much Chinese agar agar to use as a substitute for the nasty gelatine? I have done some searching on Google but info is scarce. I would prefer to take advice from a real person who has used it!

I haven't used it yet, but you could check the following. 

http://blog.fatfreevegan.com/2006/07/red-whit e-and-blue-fruit-terrine.html

http://blog.fatfreevegan.com/2006/08/fruit-ge l-babies.html

I don't know if you're still looking for advice, but you can also set gels with pectin, a natural fruit starch that you can buy in the baking aisle or near canning supplies. The guidelines that come with it will most likely be for jelly - you may want to more closely follow the proportions for jelly candies - I followed this recipe with great results: http://coconutlime.blogspot.com/2006/12/raspb erry-jelly-candy.html

Thanks for your suggestions. I did manage after some fumbling around. I brought the mixture to a boil with the agar agar until it had all dissolved then allowed it to cool a little before pouring onto the base. I got a bit too much of a set so it didn't have a nice mousse feel in the mouth, more a cheesecake, but heh, it tasted good. I'll know another time how much to use. A bonus was that it was considerably cheaper than good quality gelatine leaves and who wants pork or beef products in their dessert?!!