self employed 401 k question

[mo42nyy]

I posted this in the finance forum but I think I will get a better answer here:

I did a sep ira for 2006. For 2007 I may want to do a self employed 401k. Do you deduct this on the schedule c, or do you
deduct it on the 1040?
Im a curious because if you can deduct it on the schedule c, you would avoid paying the SE tax on that amount of income.

[broiler]

Both plans are deducted in the same place on the 1040, so you don't get a different self-employment tax benefit for either plan.