Acme and I are looking at our costs for getting to both OSCON and YAPC::NA. The problem is that at the moment it seems to be cheaper for us to fly to Miami, stay for a couple of weeks beyond the conference, and then fly on to portland before returning to London. Or at least for the airfares (significantly so, airfare for LHR/MIA is about 450 GBP, LHR/PDX is about 700 GBP, to do LHR/MIA/PDX/LHR is about 616 GBP)
The real problem there is that it is a month when we have to pay mortgages, accomodation, as well as taking a large amount of time of work. We need to find a low cost way of staying in Boca Raton in between conferences and its proving to be quite difficult.
There are a couple of avenues we have still to explore, but its all getting very complicated and confusing.