That plug is common on lcd screens - I had a couple of compaq/hp 15"s that took it that I binned a year or so ago because the panels were stuffed. I would expect there are lots like that now so you should find a PSU quite easily.
Failing that there are some new ones on ebay from hong kong for almost nothing. I have just heard it called the 4 pin power connector but there may be another name for it. Seems the polarity is a standard tho since I have used a power supply off an old laptop on a monitor just fine.