How to change avatar photo size for us non-Microsoft types!

I am on a Mac and cannot seem to figure out how to change my photo sizes so I can post an avatar. I saw the link to Microsoft powertoys but it doesn't work with Vista either (my other computer). Can anyone offer some advice for this?

RE: How to change avatar photo size for us non-Microsoft typ

for your Mac get this application (free)
http://mac.softpedia.com/get/Graphics/iZoom.shtml

for Vista get this one
http://www.vso-software.fr/products/image_resizer/

Sorry, this is way late but I will add my .02 anyways. Using macs iPhoto select your picture, click File then Export. Under the "Kind" tab, select "jpeg". Under the "Size" tab, select "small", then click "Export". It will prompt you to save it in a location of your choice, then you can load the photo to the site.