Bon,
If you feel well enough to go to the gym it can help you recover more quickly. The rule I've heard from my running coach is that if the symptoms are in the head and neck (sneezing, coughing, scratchy throat), continue to work out, but just take it easier than usual. If the symptoms are below the neck/flu-like---any vomiting, stomach issues, digestive issues, stay home and sleep. It has worked well for me.
Regardless of whether or not you work out, it's more important than ever to drink lots of fluids. Make sure you drink lots of water or herbal tea, and try to get some fresh fruits in your diet as well. Lay off the junk---your body needs nutritious food in order to recover more quickly.