SharePoint 2007 has a recycle bin - there are actually 2 of them - user recylce bins (to get your stuff you deleted) and items stay in there by default for 30 days. After 30 days they end up in the site collection admin recycle bin. You admin can restore those docs for you and I believe they stay for another 30 days so in theory you have up to 60 days of protection.
Ted