I'm shopping for SD cards and wondering if there's a real difference between brand name cards and ebay knockoffs from Hong Kong. These appeal to me because I can get almost double the memory for my money, but I don't want something with inferior performance or that will crap out in two weeks. Which should I buy?

There are certainly some crap SD cards out there. You get what you pay for (most of the time).

better to stick with name brands. i got some 8GB kingstons coming my way that i hope will enable my N800 to save a bit of power, vs the noname cards i use now.

Some of the ebay HK cheap cards aren't what they say they are. Eg. an 8GB card might only really be 4GB.

A-data, patriot, transcend, sandisk, and kingston are all common brands that have a good reputation. newegg and buy.com have been getting pretty good deals for sd cards lately. The higher class the sd cards are, the faster read/write speed you get from them (class 6 is a lot faster vs a class 2).

Is there any difference in the quality of video footage if you use different classes of SD cards?

quality has to do with what the recording source is ...diff classes of cards refer to the speed at which they can transmit data

In addition to what Mike Fila said, there's no proper authority over regulation with the printing of the class speeds. Each manufacturer tends to guarantee certain amounts of write speeds with each class however the result vastly varies from one brand to another.

I would avoid buying stuff from Hong Kong via internet and especially brand names without any warranty against workmanship. You save yourself a couple of bucks by buying stuff cheap but the quality of the product is literally thrown out the window.

Then there's pirated hardware, for instance you can get yourself products with misleading capacities. This does not specifically apply to only Kingston products but to many many other popular brands.

I've had nothing but good luck with Kingston going all the way back to my Nokia 6133. The one card I had to replace they replaced immediately under warranty.

I've had about twenty different cards in the last five years. I use Kingston in my cameras as well as my phones and have never had any problems apart from the one warranty issue which was a microSD that physically broke upon insertion. I've never seen or heard of such a thing from anything else.

I buy directly from Kingston as they usually have the best prices. Now if I could get them to use a unionized shipper like UPS or USPS it would be perfect.