I feel its important to highlight the existence of a database which is readily available on the Internet for any person who may need blood in an emergency. PakBlood.com has recently opened their doors and are actively maintaining a list of volunteers willing to donate blood whenever needed. Its armed with a great search engine which organizes the database according to blood type and also availability in the city of choice.
For all those concerned it is actually quite healthy for one to donate blood every 56 days (Red Cross), But during the process just ensure that sterile packs are used while extracting blood.
A little critique on the site if I may. Though I understand the need to display all information for the donors I feel there may be a serious problem with privacy as the contact details are open for everyone to read. I feel in an attempt to improve the site the designers could initially limit this information to registered users and then with time devise an ingenious method where the website can automatically send an SMS to the donor when needed then awaiting his response. I would have to concede it may defeat the open ended system which may prove to be a little waste of time but a little hindrance would keep away stalkers and entrust confidence to attract willing donors.
Karachi needs to step up to develop a very active local list, Step forward and enlist yourself and donate blood to save someone life
http://karachi.metblogs.com/archives/2006/10/pakistan_blood.phtml