For what it's worth, I just received a Class 6 Transcend Micro SDHC 8 gig card that I ordered from New Egg. Set me back all of $20.49 with free shipping. It replaced my Class 2 4 gig. Popped it in my Blackberry and started filling it up.

From what I have seen most of the cards on sale at the Office super-stores tend to be class 2. They have the faster ones but they are a little more expensive, and tend to be by the cameras rather than by the memory sticks where I was looking.

The faster the card is, the quicker your camera will be able to take the next picture. I do notice the video camera on the blackberry saves a little quicker with this class 6 card than the old one.