Preserve Raw vs Embed Raw in DNG

Peter,
I got a lot of good info the other night in Miami so thanks for coming down.

I have two questions, one you say on dpbestflow.org that you recommend preserving the raw or embedding it, but I can only find the option to embed it not to preserve it. Where do I find that option in the stand alone converter or is it only in Camera Raw or Lightroom?

Secondly, I thought I heard you say the other night that you could convert Tiff and JPEG files to DNG or did I misunderstand what you were saying? I have tried it but it doesn't seem to work so I must be wrong.

Thanks,
Dennie