Tegaderm!
Good stuff but generally not something I'd use to treat an injury.

I'm an occupational first-aid attendant and licensed EMR with several years experience. When it comes to first-aid supplies my wife (also an OFA and a former nurse) and I love this particular product (as do our co-workers): Hypafix Combined with a good non-stick pad underneath this makes for an all-around excellent (and simple) dressing for patent wound care.