Simple way to keep your download folder tidy

From Danny O'Brien, a nice hack for keeping your download folder tidy -- a script that deletes everything that's more than a week old. I'd like one of these to run on my ~/.Trash folder, too.
I've had bad experience with handing "delete file" powers to an automatic script before, so I'll disclaim any warranty ("TO THE EXTENT PERMITTED BY APPLICABLE LAW" as the GPL shouts), but it's pretty straightforward, and works for me: I have it in a cronjob. The tmp folder it cleans up is my default save folder on Firefox, and where I generally download everything. If I want to save anything longer than a week, I find it a place in the rest of my filing system. It's sort of like having a cleaner come around every week: occasionally you go "Garr! Where's that coffee-stained, have torn copy of last month's New Yorker! I was going to eventually get around to reading that!", but mostly your cruft just silently disappears without you noticing a thing.
the most useful simple script i have