As a rule, independant video cards are almost ALWAYS better than the stock, onboard adapters.
I'm assuming this is the card you're looking into: http://www.tigerdirect.com/applications/Se...sp?EdpNo=706688
As for "is it worth it", i'm gonna put in a big "MAYBE". It's a very good bet it's better than your current card, but if you're going to want to do more stuff in the future regarding video editting or gaming, i'd suggesting investing in a 128mb or even 256mb card. 128's are getting cheaper and cheaper by the day, but 256's are still fairly pricey.
If, in the end, all you're doing is simply watching videos and playing older games, i'd say go with the 64 card you're looking at. It's only $30, and will most likely boost performance and quality a bit.