It seems like the only way to get approval for a Bot account is if it adds to or edits information already on Wikimedia. If you try to download any images, without a bot account
Having just done this myself I feel I should share:
http://www.mediawiki.org/wiki/API:Allimages
This API document does state that you can query the images:
http://en.wikipedia.org/w/api.php?action=query&list=allimages&aiprop=url&format=xml&ailimit=10&aifrom=Albert
with the aiprop=url you are given the url of the image you are looking for.