The Amazon to MARC converter takes information from Amazon.com book records and turns it into MARC. I don't see myself using the MARC records this produces, because the records would take so much cleanup that it might actually be easier to start from scratch, but I still think it's pretty cool. Plus, some aspects could be useful for my work: I could copy and paste summary information from here and avoid (I'm pretty sure) having to hunt down quotation marks and apostrophes that Connexion doesn't like, and I could potentially use this as a starting place for call numbers and subject headings.
The IMDb to MARC converter (prototype) takes information from IMDb and turns it into MARC records. I think this converter's output is actually even more helpful than the Amazon to MARC converter's - video recording MARC records take a lot of work, because of all the name access points and various notes. This would take care of some of that work, although there'd still be a lot of fixing and fiddling to do. I love the "verify names" feature (also present in the Amazon to MARC converter). I could see this tool being especially popular with libraries that, in order to save time, have a policy of basing video recording cataloging on container information - this would probably help them save even more time. Again, as with the Amazon to MARC converter, I probably wouldn't use the MARC records produced by the IMDb to MARC converter, but there are still certain things I could copy and paste into the records I end up using in Connexion.
UPDATE: The Amazon to MARC converter doesn't just do book records - I just had it generate a record for a DVD, VHS, and CD. The "classify" information seems to be drawn from OCLC - too bad, I was hoping it could help Tracy and Trudy in those cases where they have trouble finding OCLC records that match the Contemporary World Music records they're assigning call numbers to.