301 redirect, or rewrite?

[Dragonmom]

After several years of having my oscommerce website in my root directory- I want to transfer it into its own directory. As it happens, I #*$!ed up a couple weeks ago just as Google was spidering me- and I lost my ranking, from 4th place for my most common search word to not even in the top 50 :\ I figure now is as good a time as any other to take care of this issue, while I repair the damage (I forgot to reinstall the meta tags contrib, and had mistake in my configurations file that made for some busted links)
So, my question is- how best to set up my redirects? Google has a list of 127 urls in my site, I could list them all one-at-a-time in my .htacess file, if I must- could I write a global rewrite instead? I certainly don't want to harm myself further with Google, though!

[ryan26]

If the old URLs are still indexed, perform a 301 redirect. You want to ensure two things: a) the engine understands that you have moved the location of your old content to new URLs and that they can dump them in favor of the new location, and b) the engine doesn't have a duplicate listing for a single page as you will be flagged for dupe content. If the old URLs are still indexed as your new content gets indexed, you'll likely loose a good chunk of your organic traffic and won't see it come back until you perform the 301.

Go through the hassle to fix the problem now.