The Four-Leaf Clover
The four-leaf clover is a rare mutation of the common three-leaf clover. It is a common activity for children to look for these and it is considered good luck to find one.
People who search for four leafed clovers note that some patches of ground appear more likely to contain four leafed examples and that this may be partly due to differing growing conditions such as pollution, soil composition, and other environmental factors. A countervailing hypothesis is that the varieties themselves are more accustomed and that the mutation may be a phenotype rather than a genotype.
It has been estimated that there are approximately 10,000 three-leaf clovers for every four-leaf clover.  (http://www.yokeandzoom.com/page1.htm)
According to legend, each leaf of the clover represents something. The first leaf is for hope, the second leaf is for faith, the third leaf is for love, and the fourth leaf, naturally, is for luck.
So my question to creationists is this: we know things mutate, such as a four leaf clover, so whats to stop beneficial mutations from being selected for(evolution)?
Creationist answers: "they will never mutate into anything but a clover. They will not become a tree, an animal or anything else but a different sort of clover.."
I respond: Many small changes over time will eventually make something different.
It's like saying if you keep adding 1+1+1 and so on it won't eventually reach 1,000 or 1,000,000 or 1,000,000,000.