[onitica]

I've backed out of going to graduate school after accepting to go, which is similar to a job offering since they were offering a fellowship. The only thing I felt bad about was I didn't realize soon enough that I shouldn't go, but it just wasn't the right move for me. Some people may disagree, but I think you should back out of it. There are very few companies who would have qualms about firing you if they could find a better employee to replace you or would make more money by firing you. You shouldn't feel guilty about holding them to the same standard (i.e. you found a better employer or one who offers a better deal).