The P880 is fairly slow when it comes to card writing. So a faster memory card won't make much difference in the camera. If you have a high-speed card reader and the extra few seconds matter then a high-speed card will be better when transferring images to your computer.
I started with the Sandisk Ultra II SD cards, but my memory card reader tops out at about 6MB/sec so I ended up getting a 2GB 50x A-Data card from newegg.com for $50 instead. They have them for $45 shipped now:
This seems to be about the best bang for the buck as far as SD memory is concerned. Also a good match for the P880 as the card size is close to the battery capacity. As far as brand most cards have a lifetime warranties, but at less than $50 and the prospect of still needing a warranty on your SD memory several years down the road is somewhat silly at the rate memory prices have dropped. Newegg will cover the card for the first year which is when you would see any manufacturing defects that would affect performance.