Alternative to iconv?

[OsakaWebbie]

I need to convert text between UTF-8 and Shift_JIS character sets on a hosting service that has PHP 4.3.10 installed. It is configured for handling multibyte character sets, but it apparently doesn't have whatever it needs to include the iconv() function (I tried using it, but PHP claims that it is undefined). Is there another way to convert between character sets? (The reason for my need is that I'm using a MySQL database that is UTF-8 and am adding capability to serve the data to a cell phone that only does Shift_JIS.)