Yesterday my wife had her annual pumpkin carving party. Last year our pumpkins died after two days, and by "died" I mean it was covered in black mold and smelled like rotting food...
So this year we did some research and found this site:
The TWO biggest tips that I'd say work the best are tip #1 and #2. I know since the beginning of time you've cut the top of your pumpkin in order to clean out your gourd, BUT instead of cutting around the stem.. Cut the back of the pumpkin.
And the second tip says to take your fully cleaned and carved pumpkin, dip it into cold water mixed with bleach and then let it dry. If you follow the majority of the 7 tips you should be able to have a nice pumpkin on Halloween.
Try them out and let me know how it goes, have fun!