We (2 people from De Wikisource) have experience with that service. It takes more time than announced but there 20+ books scanned for us successfully. Unfortunately there is a very few selection of German books wich are in the Open Library - BPL has a lot of German books but it is sad that only a few are available for this great service. For English books the situation is much more better.
When searching in the Open Library please note that all numbers given on the right side for "scannable" are wrong. You have to find catalog entries with at least "scannable (1)". Try e.g. search string German: scannable (1), but 183 books are scannable.
Try it out!
Klaus Graf http://archiv.twoday.net Cologne Archives Collapse News