Wanted: Campagnolo Ultra-Torque retaining pin

Anyone got a spare one I can have ?

I'm really not sure that you actually need one...I've been riding..alot.. without one for about 3 months and I'm still alive. I believe the argument for their usage is that they prevent the cranks from falling away from each other should the allen key screw mechanism linking the two crank pins come loose...but i don't buy that...surely it's not that hard to make sure that both cranks are locked firmly into each other...
i did have same problem as you...i couldn't find my retaining clip anywhere and no uk based retailers seem to sell it and i looked everywhere
Online research seemed to suggest that I would be ok without it...but if you insist on one for that tiny chance that your cranks fail...i would recommend sending an e-mail to this guy peter at http://www.vecchios.com/
It's a bike shop based in US, but this guy seems to live, sleep and eat Campag, and he offered to send me one for not that much money...something like $3.50 for the clip and $4.50 for postage...so 5 quid overall...

The retaining clip and the washer come with the BB cups, as opposed to the cranks, so you could buy a new set of BB cups for ~£15 to get the clip.

I bet you can buy them as a spare part.

Campag spare part number is CC-RE001

It's not to hold the cranks together in case the bolt falls off, because the left crank will fall out anyway. It's there to prevent end float of the crankshaft, which will wear the cups as the bearings slide from side to side in the cups. Without it, there is up to 2mm of float in the crankshaft, although the end load on the crankshaft is small unless you pedal funny and you have to overcome the pressure of the preload wave washer (FC-RE009)to move the crankshaft sideways. Long term riding without the circlip may cause accelerated wear of the cups, but as they're only £12-£15 that's not a tragedy.

^ yeah, what he said

Sourced one now, cheers all. Just didn't wanna buy another set of cups if I could avoid it, and I have.

MDCC, I have some super record cups. Can I use these with some record 10sp UT cranks? Bodge?

You can use them, the only difference is the lack of seals in the Super Record, they are not considered necessary with the CULT bearings. If your frame has a closed shell BB (some carbon frames do), it won't do any harm at all. With most metal frames, water can get into the frame and ends up in the BB shell, and the BB cup seals are supposed to keep that water and the crap it brings with it out of the bearings. AFAIK, you can retro fit the seals (CC-RE002) to the Super Record cups.