I quite like the new co-op farming on Farmville where you can start a co-op job and you have to plant and harvest a certain amount of a certain plant in a certain time period.
Once you start a job, your friends can then join your co-op and help you to get the plants harvested in the time period. If you haven't started your own job, then you can join one of your friends co-op jobs. You get your normal coins and xp rewards for harvesting your crop plus a bonus for completing a co-op job, so this can help you to climb the ranks a little faster.
Co-0p farming is also a great way to help friends out and just play a more 'friendly' game where you can be involved more with your friends.
