Last Saturday Clare and I did this with our good friends Gaz and Ruth.
http://www.avalanchepeak.co.nz/default.asp?PageID=7107
If you click on the link you can look and see if you can spot us but if not here's a few pictures.
Nice and fresh at the start

On top of the world

Gaz sprinting past us

We had to cross the river Selwyn 12 times, so it's just wade in and go for it

Thankfully it was a warm day so nott so cold once you came out of the water. You soon got used to the squelching in your boots

Nearly there

Made it but very tired. 20.3 km's and yes we were next to last :-) Even the sign was tired