I think these are created if the the 'AutoRecover' option is enabled. Probably best to keep it operational but you can turn it off in Options/Environment/AutoRecover.
HTH,
Viv

>I have no idea what they are. It is a folder structure 3 levels deep with no files: Visual Studio 2005\Backup Files\
>
>>Are they temp files that aren't getting cleaned up after you exit VS?
>>
>>>I do delete them, but next time I open the project it recreates it. There are no files in the folder, either, so I don't really understand what the heck is going on.