Swimming lanes, XCode and Visio

[Peter H.M. Brooks]

Here are a few questions - I am pretty new to Omnigaffle, so I expect 
that I might have some RTFM answers - but, if you tell me where in the 
manual, that's fine with me!

I am producing UML diagrams for processes - how do I configure 'swimming 
lanes' (aka swimlanes, swimlines or, maybe, tramlines). I mean the 
vertical (usually, they can be horizontal or both) lines that you name 
after your process agents or owners and into which you put the relevant 
tasks or questions? It's quite important to UML, so that you know where 
the end user goes, where the application works and so forth! They 
probably have another name for them, but I can't find it!

Is there any UML -> XCode interface? I'd like to design a process in 
Omnigraffle and then compile it in XCode into an application. That's 
probably science fiction just now, but is there a plan in the future? 
More importantly, is there a tool (like uml2psp) that'll take my 
Omnigraffle UML output and translate it to something that I can compile? 
What do you suggest using?

Finally, a simple question. What is the earliest release of Visio that I 
can export XML to? I've tried exporting UML diagrams to Visio (2000 and 
2003) and found the success variable at best.

What I really want to be able to do is to develop most of my UML on 
Omnigraffle, take it into the office, import it into Visio, allow other 
people to make changes to it, and then re-import it to Omnigraffle. Has 
anybody got this cycle working?

As you can see, I'm an enthusiastic new user wanting to really get down 
to working with Omnigraffle - I hope that your answers won't be too 
disappointing!!

If they are, by the way, how responsive is Omnigraffle support?