I've had a few comments and questions (thank you all very much!) about these here triangles, so I thought I'd just try and answer them all here...
I 'made up' the triangles myself. I hadn't seen them before I started making them. It is simply a case of "great now I can make squares, what else can I do with my limited crochet abilities?" At first I started making a hexagon type granny, but possibly because of the yarn/my hook, that didn't work out too well.
So I started making triangles instead. And if you can do a granny square, you can do the triangles too. You just chain one less at the start than you would for the square. After that it's exactly the same thing.
After people have started asking me about this, I had a wee look on the internet, 'cause I was sure that others must have come up with the triangles too. But to my surprise I couldn't really find any! I found a few places that have a triangle which basically looks like a square cut in half to make a triangle, but only one that is a 'proper' triangle. (The links are to patterns for each.)
There must be more people making the triangles, right? If not, why the heck not?! ;-) I am really tempted to make a 'ghan from triangles in stead of the squares that I have been considering...
The idea for the scarf came because I was just happily crocheting the triangles and then I thought I needed to use them for something and the scarf seemed the easiest thing to make. Which it was once I figured out how to stitch the triangles together. At first I was a bit annoyed that the scarf wasn't straight, but now I'm quite happy with the wavy line of it.
As for the yarn I've used, it's DMC tapestry wool, which was the only yarn I had and I wasn't using it for anything else. It is very nice to crochet with, but I won't really recommend it as it's just not very economical!