"SQL distinct" like applying of templates

Hello List,

I have a list, with many elements having equal names. The values of the
items are strings.
I want to select each different string exactly one time. Just like in SQL
while using the "distinct" option.

Example:
<list>
        <item>string1</item>
        <item>string2</item>
        <item>string2</item>
        <item>string3</item>
</list>

I want to get the following list, omitting the second node with the value
"String2".
string1
string2
string3


Is this possible woth XSLT, and how?

thanks a lot!

jan