Here's a bigger list of data types. I got this by creating every type I could and calling fetch_fields():
<?php
$mysql_data_type_hash = array(
1=>'tinyint',
2=>'smallint',
3=>'int',
4=>'float',
5=>'double',
7=>'timestamp',
8=>'bigint',
9=>'mediumint',
10=>'date',
11=>'time',
12=>'datetime',
13=>'year',
16=>'bit',
//252 is currently mapped to all text and blob types (MySQL 5.0.51a)
253=>'varchar',
254=>'char',
246=>'decimal'
);
?>