I would like to do some basic voice recording to my PC via an ordinary microphone.

I need to be able to change the voice(s) any number of ways but would specifically like to be able to have the pitch of the voice(s) change so that I can essentially have the helium-voice-effect and at the other end of the spectrum the slow-monster-voice effect.

I already have/use VoiceSFX from Blazeaudio.com but need some other pitch-shifting softwares with greater flexibility to test in my recordings.

Can anyone direct me to other softwares that suits the purpose(s) I just mentioned? I haven't been able to find any.

Thanks very much!