To candyg12l: I used the iPod Touch instructions for where to get the ipsw.
From that post:
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iPod2,1_3.0_7A341_Restore.ipsw is the iPod Touch 2g 3.0 firmware file.
iPod1,1_3.0_7A341_Restore.ipsw is the iPod Touch 1g 3.0 firmware file.
On XP they are located in
C

Documents and Settings\ YOUR USER NAME \Application Data\Apple Computer\iTunes\iPod Software Updates\
On Vista the are located in
C

Users\ YOUR USER NAME \AppData\Roaming\Apple Computer\iTunes\iPod Software Updates\
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I just changed iPod to iPhone in each instance. My latest ipsw was right there. When redsn0w asked for one, I used the iPhone1,2_3.0_7A341_Restore.ipsw, which was created tonight when I upgraded to 3.0.
Now, that being said, I'm having some problems with a number of jailbreak apps not working. I'm still working on them, though, and think that doing some SB restarts will help.
Oh, yeah - the ipsw file isn't in the zip folder, as some seem to expect. I downloaded the one that modmyi has available, but couldn't get it to work. That's why I tried the other way.
So, it's TWO downloads for jailbreaking, which is all I do. Not worried about unlocking.
And to the folks having issues unzipping: Vista gives my headaches with that as well. I had to use a separate program to get the .exe to unzip properly.