There are options in myPHPadmin for Collation on tables and Collation on fields. Generally does it matter? Since I can choose not to fill such options. The programs Ive been using for data conversion fill them for me usually as latin1_swedish_ci on the table and column level.
This page explains it pretty well http://www.informit.com/articles/article.asp?p=328641&rl=1
In practical terms, I have never paid much attention to them... the default collation seems to work for every case that I have run across. Perhaps you would want to use a different collation if you were storing chinese or japanese text though.