I have one from the gap outlet that i really like, sorry, no link, but if theres an outlet near you, they have a smilar one thismyear too (actually its exactly the same, just different colors).
I have this jacket too, but I think it is a bit heavier than light weight. I'll probably stop wearing this one once the temp picks up.
True, it isn't all that lightweight. I wore it today, in cold wind (it's so great for that!) and was warm with a l/s and tank under. I just figured in warmer rainy weather, I'd stick to a tank or just sports bra under.
I can't seem to find the one I have... It's a Nike very similar to this one. It's very very light- there's mesh on the sides. It actually lets the wind right through. Not so great at 9 degrees and very windy this morning, but it's great!! I overheat usually, so breathable is a good thing!