A good realtime pitch shifter ?

[Scottxx]

Any good realtime pitch shifter that is good on guitar ?
I tried the one in Amplitube 3 its not that bad. Is there any other be worth while ?

 

[Sacha]

Seems to be a difficult thing to get right in my experience, hardware seems to track better, stuff like the Eventide pedal is really good for instance.

 

[Loren Littlejohn]

Yeah I looked for something like this a while ago. The problem I found was the word "realtime." Anything good was expensive and used a lot of CPU power.