i think you can use sudo something but better get that advice to a UNIX-MAC geek!
GEEK from Sherlock Dictionary
Slang 1 a. A person who is single-minded or accomplished in scientific or technical pursuits but is felt to be socially inept.
2. A carnival performer whose show consists of bizarre acts, such as biting the head off a live chicken.
OUR LIVING LANGUAGE:
Our word geek is now chiefly associated with student and computer slang; one probably thinks first of a computer geek,
Click the file/folder and go Get Info
Click the "Ownership and Permissions" tab
Click the lock to authorise yourself
Where it says "Owner" in this tab, select your username from the drop down menu and then "Read and Write" from the menu directly below.
You should then be able to delete the file. That would be the Mac was of doing things. The UNIX way (The command line entry above) is faster.
What if you've got a file (on the desktop for e.g.) that is permanently "in use" by another app.
This is the message I get for a couple of files that popped up one day after I d/l'd some stuff with IE. I can't open them and I can't delete them regardless of the ownership b/c the system feels they are "in use".
I had the problem you talked about, and with the same origin, a file created by Explorer that couldn't be deleted. I ended up opening it with Textedit, adding a couple of keystrokes, then saving it as a textedit file. It deleted normally after that!