[_delirium]

This is the current federal law on the subject: http://www.law.cornell.edu/uscode/search/display.html?terms=...

Basically, you are immune from liability unless you either: 1) are a licensed professional acting within the scope of your employment, in which case normal professional liability rules would apply; or 2) do something that a court finds grossly negligent.

[noonespecial]

Unfortunately, it may cost you quite a bit of time and money to convince said court that what you did was not grossly negligent should someone press the issue.

[chii]

No one in their right mind would press the issue, lest it causes a chilling effect on bystanders attempting to help someone in need.

[noonespecial]

Lawsuits and "right mind" seldom are within shouting distance of one another.

http://suite101.com/article/good-samaritan-risks-lawsuit---s...

And just for a twist:

http://abovethelaw.com/2011/08/lawsuit-of-the-day-good-samar...