Strange file on my desktop - ~

Factual Questions
1

Yesterday, I noticed a strange file on my desktop. It seems to be some kind of a system file, I can not open it. The file name is this: ~ .

The only information I can get from properties is the file size.

A search on files named ~ shows 3 files with this name, located in

C/Documents and Settings/(my user name) (180kb)
C/Documents and Settings/(my user name)/Desktop (175kb)
C/Programs/Outlook Express (172kb)

Any idea what this file could be and if I can safely delete the one on my desktop?

Thanks.

2

Lately I have been getting it too when I mess with the Adress Book and I believe it is a backup (or temp backup) of the Address Book and can be safely deleted. At least I have just been deleting it and found no problems yet . I have also found it in folders other than the desktop.