Wayno - I'm not a subscriber, maybe one day when I have the money however!
Strider - That looks pretty cool, I don't know how it would work without a hiking pole as I don't walk with them. Do you know?
PerfectlyDark - I bit the bullet this morning and ended up making my own fly / poncho combo. Below are some photos of it.

- All rolled up

- Laid out flat

- The gaffer tape tie points and fishing line guys

- The slit for my head when used as a poncho, which is taped over when used as a fly

- Poncho mode - No need for a hood when you have a big hat! (hopefully...)
The dimensions are 1.2m x 2m and it weighs around 230g. I'm going to use it on a overnight bushwalk this weekend, so I'll let you all know how it goes when I return.