The easiest way I have reduced a picture is to email it to myself. Depending on your software it usually asks if you want to reduce the size before sending. Select 640x480 and send it.
There are two ways to get enough Cubs. One is to continue to accumulate more and more. The other is to desire less.
I resize mine in paint. ----- Have Flickr account but its a hassle to upload them then download them again, so I found if they are re-sized (640x480), I can post them direct from my computer cutting out many steps.