Here is the code to put a search box on your site that will search Yoddle. You may alter this to suite your needs. Feed back welcome.
Code:
<center>
<form method="POST" action="http://www.yoddle.net/yes/cgi-bin/yes/smartsearch.cgi">
<input type="hidden" name="username" value="draco">
Yoddle Search:
<input type="text" name="keywords" size="20">
<input type="submit" value="Search" name="search">
</form>
</center>