what is this? - Jelly fungus

I don't even know whether it is animal, mineral, or vegetable in origin! I found this little lump of jelly hanging on the branch of an aspen tree down by the river. I've never seen anything like it before. The tree seems fine (it's winter and raining). When I first saw the thing I thought it was the paper case of a wasp nest, but it is definitely a jelly type material, quite translucent, attached to the twig at about 5 feet off the ground.

Look up "peach tree gum" .  May be that is Aspen tree gum?

Maybe a jelly fungus?

Looks Like tree gum to me.

Thanks for your suggestions everyone. Having looked a bit more closely - I believe it is actually a willow tree I spotted this on, and when I went down in the sunshine I saw quite a bit glowing in the sunshine on the other trees by the pond. The jelly has gone a bit more amber coloured and shrivelled in the frost. I found look-a-like photos on wikipedia via this blog So I think I have Exidia recisa or something very similar.

(via wikipedia)
The size they give suggest mine are a bit small, they fruit on dead or dying wood - probably the trees are a bit congested, willow likes more light so I'm not too worried. It's just interesting to see fungi up a tree like this :)