I am having a similar problem... I bought a MacBook Pro that has gone through 6 hard drives & repairs by Apple since August, so it is far from reliable, but that's not why I'm posting, but it IS why I just bought a used ipad..
I travel & am tired of carrying 2 laptops (my old reliable G4 Powerbook and the new one that keeps killing hard drives) so I bought a used ipad 1st gen 64G wifi, 3G (although I only plan to use the wifi). It arrived today & worked perfectly, but had the previous owners data on it, including over 1400 songs & 800+ photos. I was deleting one-by-one, then found the DELETE & RESTORE command in settings. It has now been on the black screen with just the Apple logo (showing a crack in the apple) and the spinning compass-like lines for 7 hours! Could it still be deleting & restoring? Or is it not finding an operating system? I had not regisered it or synced it to any of my computers (I own the MacBook Pro, and the last model desktop with Snow Leopard, and the old G4 Powerbook. If I attempt to sync it with one of my computers, will it restore the OS & Apps on the ipad? I had assumed the command I found in SETTINGS would restore the factory settings, but I just have the black screen with the Apple & spinning lines & cannot even power it down. Nothing happens when I hit the SLEEP button or anything others. It seems stuck in this mode. HELP!