If anyone doesn't have any games to test ScummVM with, you can download some demos of Lucasarts/Humongous games which use Scumm (Script Creation Utility For Maniac Mansion) & the demos are at http://www.scummvm.org/demos.php .
If you want to purchase the Lucasarts games, goto EBAY, Amazon.com Zshops, et al & look for the Lucasarts Archives (there are several of these archives) & each one of these archives included several Lucasarts games each.
On the demo page at http://www.scummvm.org/demos.php , you will see a section which says Humongous Demos. Humongous is Humongous Entertainment which is a company which makes games for kids & all of their older games are written using Scumm. Humongous Entertainment was created by Ron Gilbert who was the person who created Scumm & he also created the first game which was written in Scumm & the game was Maniac Mansion. Humongous Entertainment is now owned by Atari (Infogrames). Their site is at http://www.atari.com/atarikids/. You can purchase some of their games at http://www.atari.com/atarikids/ but, unfortuntely, some of their games can't be purchased from their site. If you want the Humongous Entertainment games, I suggest going to EBAY, Amazon.com Zshops, et al to find a used copy. Basically put, only the Humongous Enetrtainment games listed at http://www.scummvm.org/compatibility.php are the ones which use Scumm.