First off, I love GrowlTunes. When i'm listening to my iPod, I often glance up to the top right corner of my field of vision when the track changes before catching myself. However, the feature that fetches album artwork from Amazon slows it down immensely for me. Unlike most people, I listen to a lot of unofficial live shows that do not have covers and that are not listed on Amazon, so the search is ultimately fruitless, and the Growl alert doesn't appear for 10-15 seconds. As for the actual albums, I actively seek out artwork for my library. So basically, either the tracks have artwork already, or they don't have artwork listed on Amazon anyway, so the Amazon feature is useless. I also live in a college dorm with a lackluster internet connection which frequently drops out, and in the the absence of an internet connection GrowlTunes simply waits. A few moments ago, a song played almost in its entirety before the Growl alert appeared because my connection was slow. Anyway, I would like to turn off the Album Art fetcher.
This post started out as a question on how to turn this feature off, but I figured it out, so here's how to do it in case someone is in a similar situation:
Find GrowlTunes.app. It will presumibly be in your Applications folder, but maybe you stuck it somewhere else. Ctrl+click it and select Show Package Contents. Open the Contents folder, then the PlugIns folder, and drag "GrowlTunes-ARTchive.plugin" to the Desktop. You don't want to delete this file, so stick it in your main Backup folder, or create one in the Contents folder in GrowlTunes.app. Restart GrowlTunes, and it is no longer active, and there will not be a delay in songs which do not have artwork. Ta-Dah!
Yeah, I know, really simple solution. I should have thought of it sooner, but I didn't. Now hopefully I've saved someone unfamiliar with OS X the embarrassment of posting such a simple question.
Again, great programs, guys. I use Growl with pretty much everything, and I use HardwareGrowler as well.