Ok this is the situation.  We have replaced our old ASP site with a DNN one.  So now we want to do 301 redirects on the old pages to the new DNN ones.  Those old pages though no longer exist in the web directory.  So what we've done is setup a custom 404 page that basically examines the incoming url and matches it with one in a case statement.  If there is a match then code as is shown below is run:

Case "/items/about_storacles.asp"
            sReturn = "http://www.amazingfacts.org/FreeStuff/BibleStudies/tabid/102/Default.aspx"
            Response.Status = "301 Moved Permanently"
            Response.AddHeader "http://www.amazingfacts.org/items/about_storacles.asp", sReturn
            Response.redirect (sReturn)

If no match is found then the Page Not Found message is shown.  Is this ok?  Is there any penalty for doing it this way?

Wow I had not thought of that ... well thats definitely not good.  What would be the options to do a 301 redirect on a page that no longer exists to the new page?

Yeah I was thinking along the same lines.  I think thats likely the best solution.  Better safe than sorry.

Thanks for your help!