Jivebomber - as Tom East correctly says, the IPA is the only organisation to take a proactive stance against flagging out, so the simple answer is join the IPA!
I do, however, feel strongly that a distinction should be drawn between those countries that permit UK pilots to operate there (whether individually or on wet leases) and those that don't.
The latter category seems to be composed primarily of one country - the USA - and I would suggest that action initially be taken against US aircraft and crews on wet leases to EU companies.
If no technical or other assistance is provided to them - ie they are embargoed - then the managements of the companies that have leased in the aircraft will realise that it wasn't so good a deal for them in the first place; they then cancel the lease with the US operator and the US operator then hopefully puts pressure on the US government to make a level playing field.
As for other (especially Icelandic) operators - that's a slightly more thorny issue and one which is going to get thornier with the EU expanding to incorporate a number of Eastern European countries. There, you have people like the Czechs who are good pilots but who are prepared to work hard for a pittance - as Ryanair discovered to their delight. Of course, one of the benefits of EU membership is free movement of labour.
Air Atlanta of course employs a large proportion of Americans because the Icelandic aviation authority accepts FAA licences unlike most other JAA countries.
This time, I suggest that some action is taken regarding this issue rather than just talking about it - what do you say, people?