This news is a bit old, but for those who haven't heard, the time may be close when everyone can be a universal blood donor (we should all be donors anyway). A company is currently conducting clinical trials on an apparently inexpensive method to use bacterial enzymes to strip off the unique chemical markers that are responsible for blood "types". Once stripped off, you basically end up with O type blood, which anyone can receive. Pretty cool news.

Imagine a mass casualty situations, like a major earthquake, where doctors could get blood donations from local volunteers for use on the injured even if the roads are messed up and its difficult to shuttle around units of blood. I remember when me and everyone in my NYC office went and donated blood right after 9/11 even though no one had specifically called for blood donations, that I recall. It was just a way for regular people to try and help out. If all those pints of extra blood collected could have been turned into O type blood--wow, that could've helped people all over the country.