Cool. Ask and ye shall receive. This from Craig (thanks):
"This was a common technique with analog tape: Slow it down or speed it up, sing along, then return the speed to normal and the voice would be on pitch but have a different formant and character. Here’s how to do this with Sonar.
1. Create a premix of the song that starts at the beginning. Mute all other tracks.
2. Open the premix in the Loop Construction window.
3. From the Clip drop-down menu, enable Stretch On/Off.
4. Move the Threshold slider all the way to the left (0%) so all the markers disappear. This is very important.
5. The two right-most fields adjust semitones and cents respectively. Do not enable the Pitch button! That will just confuse things. Cents will adjust +/-49 cents which should be enough. If not, for example if you need to make the pitch 70 cents sharp, set semitones to 1 and cents to -30. (For Chipmunk effects, set semitones to +12 .)
6. After adjusting the pitch, create a track and record the new clip while monitoring the premix.
7. If you started recording anyplace other than the beginning, slip edit the new clip to the beginning, bounce the clip to itself to add this extra length, then open the clip in the Loop Construction window.
8. Repeat steps 3-5, but this time, adjust pitch equal and oppositely. For example if the premix was -36 cents, set cents for the new clip to +36.
9. Bounce the new clip to itself, and now it will be at the correct pitch and tempo but with a different formant and character. You may need to trim the end, as Sonar will still think this is a loop and repeat part of the beginning. You can now delete the premix."