Mixing character sets in Apache2?

I'm about to upgrade my web server system to SuSE 9.1.. As both SuSE and Apache runs in Unicode mode this poses some headache.. I have several web sites hosted on my systems, and more or less all of them runs in ISO8859-1 mode, which in turn isn't a big problem since I can tell Apache2 to run in that mode. However, I'd like to be able to mix sites that runs in ISO8859-1 and in Unicode modes on the same Apache2 server. Can this be done transparently? Does it need some special parameters in each virtual hosts configuration file? Please advice. Anders Norrbring