On a server -> http://minecraft.dk/forum/viewforum.php?f=8 , if you wish to apply . I don't own the server though, it's just a great community and a nice place to chill. Everything is really structured and organized, so no unfair deals like admins spawning, etc.
You should check out YouTube user "GenerikB" for his fully automatic melon farm. He made rows of melons and then made the last one connect to a BUD switch, so when it grows it automatically harvests them all. Also, he uses water canals to carry the melon slices to a central location in his underground base.