Is "computational biology" different from "bioinformatics"?
I found this post by Russ Altman quite good.  Below is his opinion about the two similar but distinct fields:


  Computational biology: the study of biology using computational
  techniques.  The goal is to learn new biology, knowledge about living
  sytems.  It is about science.
  
  Bioinformatics: the creation of tools (algorithms, databases) that
  solve problems.  The goal is to build useful tools that work on
  biological data.  It is about engineering.


Just as a note:

This is just one persons opinion and I have heard many other definitions for both of these terms.  For example, one person I know mentioned that he believes computational biology is concerned with very theoretical research such as NP-hardness (ie. articles published in the Journal of Computational Biology). Other people think that bioinformatics is an applied field that is essentially using already published tools.