I agree that saying keep the government out is a knee-jerk reaction, and a sound libertarian approach involves much more than just addressing the response to an oil spill. There is a brief and somewhat scattered discussion on this topic here:http://www.lppa.org/smf/index.php?topic=34426.0
Perhaps you could bring some focus to that thread.
This issue encompasses a host of other issues, including the nature of property and rightful ownership of things like land and natural resources. It also involves responsibility for pollution of the natural environment and the policies of the federal government toward resource extraction and pollution. There are several topics of discussion on these issues if you care to look at them here (note: You must be signed onto the forum to post to these boards):http://www.lppa.org/smf/index.php?topic=34020.0
There is no doubt that government involvement can be a big problem, but it is often not where even many Libertarians think the problem lies. Certainly a federal government policy of having cheap energy does not help the situation. An incoherent and often contradictory approach to protection of the natural environment on the part of the federal government and many states does not help matters, either.
I think a more fundamental problem is when government works to secure privilege over individual rights. I have no problem with there being privilege, but when privilege and rights collide, it should be privilege that gives way. This is where the concept of limited government comes in. It is not necessarily less government, but less authority of government to subvert human rights and a smaller scope of government to limit the promotion and enforcement of privilege.
It is not that the government should not be involved at all, but it should be involved in a manner that preserves the rights of people to enjoy, use and access the commons. Government should not be promoting cheap energy on one hand and then decrying the result of rampant enforcement of corporate privilege with the same hand. If you look at the referenced discussions, perhaps you will begin to get a picture of what a libertarian answer may be. How it can be implemented is another question entirely.