In fact there is a kind of UK YC inside YC. The UK guys really stick together and help each other out. If you can get a hold of any of them I'm sure they'll point you in the right direction.
Papers and immigration are always a difficult issue. In most cases you can get a work visa or whatever visa lets you attend conferences in the US and it will be enough for the 3 month YC session.
The blogs in particular may hold useful info for you regarding getting visas and working in the U.S. plus the journey in startup as a whole - I particularly like http://www.kulveer.co.uk and http://blog.harjtaggar.com who are the http://www.auctomatic.com guys as they give a good level of detail throughout their journey.
However, http://www.techcrunch.com/2008/05/02/coming-to-america-getti... (or http://is.gd/1Vrf in short) by Peter from ClickPass could be what you were referring to and probably holds most of the answers you want in the most succinct form.
Anyway, I'm sure if you contact them they may be answer specific visa questions from their experience. Hope this helps.
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http://www.auctomatic.com
http://auctomatic.com/about
http://news.ycombinator.com/user?id=kul
http://www.kulveer.co.uk
http://twitter.com/kul
http://news.ycombinator.com/user?id=harj
http://blog.harjtaggar.com
http://twitter.com/harjeet
http://news.ycombinator.com/user?id=pc
http://www.collison.ie/
http://twitter.com/patrickc
[John Collison]
http://twitter.com/collision
http://snaptalent.com
http://news.ycombinator.com/user?id=sharpshoot
http://sharpshoot.blogspot.com/
http://twitter.com/sharpshoot
http://www.songkick.com/
http://www.songkick.com/team
http://news.ycombinator.com/user?id=ian
http://twitter.com/soundboy
http://news.ycombinator.com/user?id=petesmithy
http://twitter.com/petesmithy
http://www.clickpass.com/
http://news.ycombinator.com/user?id=immad
http://www.immadsnewworld.com/
http://twitter.com/immad
http://news.ycombinator.com/user?id=petenixey
http://www.webkitchen.co.uk/
http://twitter.com/petenixey
http://webmynd.com/
http://webmynd.wordpress.com
http://news.ycombinator.com/user?id=amirnathoo
http://twitter.com/amirnathoo
http://www.scoopler.com
http://news.ycombinator.com/user?id=ajmalasver
http://blog.projectbluespark.com/
http://twitter.com/_aj
http://news.ycombinator.com/user?id=dilanj
http://meonearth.blogspot.com/
http://twitter.com/_dilanIn case anyone wants to attend and does not know where/when it is, hope this helps...
Hacker Meetups London
04 September 2008
Flat 1,
103 Commercial Street,
London
E1 6BG
(Five minutes walk from Liverpool St tube)
(Google map: http://is.gd/4zZ)Here was a previous discussion on the topic: http://news.ycombinator.com/item?id=158969
searchyc.com is your friend.
If it's the other way (in Holland at least) it will be easiest if one of the founders/employees can be recognized as an knowledge migrant.