SDHC card - Class 2 vs Class 6

[soons]

Hi clubsnappers,

I am planning to purchase a SDHC 8GB card from the up-coming ITshow.
However, I am thinking whether I should save a little more buck on choosing Class 2 Memory card over Class 6 SDHC.

I have used a Sandisk SDHC 4GB Class 2 and use it for burst shot and Video recording + Snapping on my Canon S5 IS.

I am wondering if there is any big difference using SDHC class 2 vs class 6. Anyone who is using Canon S5 IS can share your view.