I am thinking of trying 180mm cranks as an experiment

Please - I don't want to hear debate on the benefits or not of 180s, I want to try them for myself.

However

Who actually makes 180mm cranks?
In the past it was only the top spec cranks. I can think of Dura Ace, and Record, and lightening. But I don't know of any others.
Do the new campy/fulcrum cranks come in 180mm?

SRAM Rival
http://www.ebay.com/sch/i.html?_nkw=SRA ... mm&_sop=15

As you say, with Campy it's Record UT only in standard chainrings. I have a set.

_________________
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

I'd go for the cheapest set I could find if it's just an experiment, like SRAM Apex (£80 ebay UK)
I think Campy's new OT cranks only go to 175, DA9000 have a wide range of ring sizes in 180 though.

Do Fulcrum also do 180mm cranks? Checked thier website but can't see any reference to what lengths they offer

Forget Fulcrum. You won't get a better deal on Record than this

http://www.velomine.com/index.php?main_page=product_info&cPath=86_294_383_384&products_id=1335

and BTW, it's a little secret, but 10-speed cranks work fine on 11-speed drivetrains.

_________________
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

.