Some of our best park days have been in the rain. It really seems to thin out the crowds. So, if your crew can, just go w/ the flow (unless of course there is lightening). Remember to pack poncho's. Other options would be places like Disney Quest if it's looking like an entire day of rain, and you don't want to trudge through the parks. However, DQ tends to be more crowded on rainy days. Also, if in the parks it's a good time to go hit up those indoor attractions that take awhile. Like Ellen's Energy Ride, American Adventure, ect.