If you need a tool to ease grabbing hi-res album art from various sites, you might like my new creation that can be used either as a userscript or as a bookmarklet/favelet in your desktop browser.
Stig's Art Grabr is a script that will help you fetch big size album art from various sites like allmusic.com (1080px wide cover art), bandcamp.com (User uploads, various sizes), itunes.apple.com (various sizes - Tip: Use musicdiner.com, fnd.io or labs.stephenou.com/itunes to search in iTunes' catalog. Grabr has direct support for these sites, so you don't have to follow links to itunes to grab the images), last.fm (User uploads, various sizes. Also works with artist photos, not only album covers), soundcloud.com (User/artist uploads, various sizes) and play.google.com (1200px wide cover art). And some other sites are also supported...
Install Stig's Art Grabr from Greasy Fork. Can be installed either as a userscript (requires a browser-addon like Greasemonkey, Tampermonkey, Violentmonkey or similar), or as an bookmarklet/favelet.
Stig's Art Grabr replaces my old bookmarklet.