Rated 4 out of 5 stars

Can foxyspider download photos from facebook?

This review is for a previous version of the add-on (0.94). 

FoxySpider and Facebook

Absolutely! Set FoxySpider to get images ("embedded files"). While visiting a galley on Facebook middle-click FoxySpider's button, and set the following advanced filter: http://www.facebook.com/photo.php?fbid=* (you can notice yourself that all the photo pages have the same prefix). Press OK to initiate a precise crawl session to get the images from the photo pages of the Facebook gallery you visit.
I have uploaded a video to FoxySpider's page on Facebook, showing the exact procedure: http://www.facebook.com/video/video.php?v=149263745125666

Rated 4 out of 5 stars

Need an option to limit by url, so e.g. https://addons.mozilla.org/en-US/firefox/addon/ will only download links starting with this url

This review is for a previous version of the add-on (0.56). 

URL limit

This feature is scheduled for a (near) future release. Currently you can limit the crawl to the root domain (for example: addons.mozilla.org) by selecting "Stay within root page domain".
Update: The current versions support this kind of "advanced filter" (accessible by middle-clicking the FoxySpider button).