I had a thought. After looking at Amazon's most excellent EC2 system again I realized how simple it would be to offer batch recommendations via EC2. You upload your data to S3, run a machine image I provide parameterized with the file location, it crunches, copies the results back, shuts down. It's attractive since they offer 8-way 15GB machines and the algorithms can easily exploit this to the limit, making it really efficient too.
I was thinking of developing an AMI for this separately and offering it as a for-pay commercial service -- Amazon makes that pretty easy. (It would hardly be a big money maker -- a couple dollars per hour is probably the highest reasonable price to charge -- but would sorta pay for its own development.) I think it will be interesting to try as a proof of concept. It's a solution that still doesn't scale to huge data sets, but I think a 15GB machine would still work for large-ish data sets (~100M ratings) and its exactly those small- to medium-sized applications for which it might make sense to outsource this. Sean
